The half life of a substance is defined as the time required for the substance to decrease by half. If the weight of a substance begins at 128 grams, and the half life is 7 years, what will be the weight of the substance after 28 years?

The solution of the given logarithmic equation is x = 28.1

Here we have the logarithmic equation:

4*ln(x - 8) = 12

And we want to solve this for x.

Remember the relations:

[tex]ln(e^x) = x\\e^{ln(x)} = x[/tex]

First, we divide both sides by 4:

[tex]ln(x - 8) = 12/4 = 3[/tex]

Then, if we apply the exponential equation to both sides of our equation, we get:

[tex]e^{ln(x - 8)} = e^{3}\\\\x - 8 = e^3\\\\x = e^3 + 8 = 28.1[/tex]

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5. Alternate interior angles: ∠1 ≅ ∠5; ∠5 ≅ ∠7 and ∠4 ≅ ∠6

6. Alternate exterior angles: ∠3 ≅ ∠9 and ∠2 ≅ ∠8

7. Corresponding angles: ∠2 ≅ ∠6; ∠3 ≅ ∠7; ∠5 ≅ ∠9; ∠4 ≅ ∠8 and ∠1 ≅ ∠3

8. Vertical angles: ∠2 ≅ ∠4; ∠3 ≅ ∠5; ∠7 ≅ ∠9; and ∠6 ≅ ∠8 .

9.  ∠1 and ∠7.

If two lines that are cut across by a transversal are parallel, the following special angles are formed:

Given the image given, we can identify the following special angles:

5. Alternate interior angles: ∠1 ≅ ∠5; ∠5 ≅ ∠7 and ∠4 ≅ ∠6

6. Alternate exterior angles: ∠3 ≅ ∠9 and ∠2 ≅ ∠8

7. Corresponding angles: ∠2 ≅ ∠6; ∠3 ≅ ∠7; ∠5 ≅ ∠9; ∠4 ≅ ∠8 and ∠1 ≅ ∠3

8. Vertical angles: ∠2 ≅ ∠4; ∠3 ≅ ∠5; ∠7 ≅ ∠9; and ∠6 ≅ ∠8 .

9.  ∠1 ≅ ∠3 and ∠3 ≅ ∠7. So the two angles would be ∠1 ≅ ∠7.

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The equation represents a population of 370 animals that decreases at an annual rate of 11% is [tex]p=370(0.89)^{t}[/tex].

It is defined as the function that rapidly decreases and the value of the exponential function is always positive. It denotes with exponent y = a^x

where a is a constant and a>1.

Given that,

A population of 370 animals that decreases at an annual rate of 11%

a = 370, r = 11%

p = [tex]a(1-r)^{t}[/tex]

 =  [tex]370(1-0.11)^{t}[/tex]

p  =  [tex]370(0.89)^{t}[/tex]

Hence, The equation represents a population of 370 animals that decreases at an annual rate of 11% is [tex]p=370(0.89)^{t}[/tex].

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Step-by-step explanation:

x^2 +4x +4 -7 is

y=x^2+4x-3

Answer: g(x)=(x+2)²-4.

Step-by-step explanation:

g(x)=f(x)+3

g(x)=(x+2)²-7+3

g(x)=(x+2)²-4.

Answer:

y = - 5x² - 10x + 2

Step-by-step explanation:

y = - 5(x + 1)² + 7 ← expand (x + 1)² using FOIL

  = - 5(x² + 2x + 1) + 7 ← distribute parenthesis by - 5

 = - 5x² - 10x - 5 + 7 ← collect like terms

 = -5x² - 10x + 2 ← in standard form

Answer: y = -5x² - 10x + 2

Step-by-step explanation:

Given quadratic function

y = -5 (x + 1)² + 7

Given requirement

Quadratic Standard Form: y = ax² + bx + c

Simplify the exponents

y = -5 (x + 1) (x + 1) + 7

y = -5 (x² + x + x + 1) + 7

y = -5 (x² + 2x + 1) + 7

Expand the parenthesis by distributive property

y = (-5) · x² + (-5) · 2x + (-5) · 1 + 7

y = -5x² + (-10x) + (-5) + 7

y = -5x² - 10x - 5 + 7

Combine like terms

[tex]\Large\boxed{y=-5x^2-10x+2}[/tex]

Hope this helps!! :)

Please let me know if you have any questions

Answer:

Step-by-step explanation:

y=-1/2x+6

The profit is Rs.4800.

When, in a transaction, the selling price is greater than the cost price, it means we earn a profit. It is calculated with the help of the formula: Profit = Selling price - Cost price.

Given that,

S.P =$6000

C.P = $6000

If, 1$ = Rs.115.4 (in cost price)

  1$ = Rs.116.20 (in selling price)

Then,

C.P =  Rs. 115.40×6000

S.P = Rs.  116.20×6000

Then,

Profit = S.P-C.P

         =  116.20×6000 -115.40×6000

         =  (116.20-115.40)×6000

         = 0.80×6000

         =  Rs.4800

Hence, The profit is Rs.4800.

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======================================================

Explanation:

To go from gallons to fluid ounces (abbreviation fl oz), we multiply by 128

For example, 2 gallons becomes 2*128 = 256 fl oz as shown in the table.

Another example: 3 gallons = 3*128 = 384 fl oz.

Therefore, 6 gallons would be 6*128 = 768 fl oz.

To go in reverse, from fl oz to gallons, we divide by 128.

Answer:

cot x

Step-by-step explanation:

using the identities

csc x = [tex]\frac{1}{sinx}[/tex]

sin([tex]\frac{\pi }{2}[/tex] - x) = cos x

then

csc x × sin ([tex]\frac{\pi }{2}[/tex] - x)

= [tex]\frac{1}{sinx}[/tex] × cosx

= [tex]\frac{cosx}{sinx}[/tex]

= cot x

By working with percentages, we will see that they served 56 salmon filets.

Here we know that the restaurant served 70 specials in total, such that 80% of these were salmon filets.

So we just need to calculate what is the 80% of 70.

This is just given by:

70*(80%/100%) = 70*0.8 = 56

This means that they served 56 salmons filet.

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The correctly matched quadratic functions are given as follows:

Quadratics are polynomial equations of the second degree, which means that they contain at least one squared term.

Quadratic equations are another name for it. The quadratic equation has the following general form: ax2 + bx + c = 0.

Recall that:
f(x) - a (x -c) (x - d)

where

Part A) First graph

We are given to know

The solutions or zeros of the first graph are

x=-1 and x=3

The parabola open up, so the leading coefficient a is positive, the function therefore, is equal to

The vertex is equal to the point (1, -4)

Substitute and solve for a

-4 = a(1-3)(1+1)

-4 = a(-2)(2)

a = 1

Hence, the function is equal to f(x) = (x-3) (x + 1)

Part B) Second Graph

We are also given to know that

The solutions or zeros of the first graph are

x=-3 and x=1

The parabola open down, so the leading coefficient a is negative

The function is equal to f(x) = a (x-1)(x+3)

Find the value of the coefficient a

The vertex is equal to the point (-1,8)

to solve for a, we must substitute:

8 = a(-1-1) (-1+3)

8 = a(-2)(2)

a = -2

Hence, the function is equal to: f(x) = -2 (x - 1) ( x + 3)

Part C)

We are given to know that the solutions or zeros of the first graph are

x=-2 and x=6

The parabola open up, so the leading coefficient a is positive

The function is equal to f(x)  = a(x-6) (x+2).

Find the value of the coefficient a

The vertex is equal to the point (2,-8)

We substitute and solve for a:

-8 = a(2-6) (2+2)

-8 = a(-4)(4)

a = 0.5

Hence, the function is equal to f(x) = 0.5(x - 6) (x + 2)

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The value of integration of y=16-[tex]x^{2}[/tex] from x=-1 to x=1 is 94/3.

Given the equation y=16-[tex]x^{2}[/tex] and the limit of the integral be x=-1,x=1.

We are required to find the value of integration of y=16-[tex]x^{2}[/tex] from x=-1 to x=1.

Equation is relationship between two or more variables that are expressed in equal to form.Equation of two variables look like ax+by=c.It may be linear equation, quadratic equation, or many more depending on the power of variable.

Integration is basically opposite of differentiation.

y=16-[tex]x^{2}[/tex]

Find the integration of 16-[tex]x^{2}[/tex].

=16x-[tex]x^{3}/3[/tex]

Now find the value of integration from x=-1 to x=1.

=16(1)-[tex](1)^{3}/3[/tex]-16(-1)-[tex](-1)^{3}/3[/tex]

=16(1)-1/3+16-1/3

=32-2/3

=(96-2)/3

=94/3

Hence the value of integration of y=16-[tex]x^{2}[/tex] from x=-1 to x=1 is 94/3.

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Answer:

24.315°

Step-by-step explanation:

First use the pythagorean theorem to get the missing side since this is a right triangle.

a^2 + b^2 = c^2 →

b^2 = c^2 – a^2 →

b = (c^2 – a^2)^½

b = (17^2 – 7^2)^½

b = (289 – 49)^½

b = √240.

Then use the law of cosines to find the angle in between.

b^2 = a^2 + c^2 - 2ac * cos(B) →

b^2 - a^2 - c^2 = -2ac * cos(B) →

a^2 + c^2 – b^2 / 2ac = cos(B) →

cos^-1(a^2 + c ^2 – b^2 / 2ac) = C →

B = cos^-1(a^2 + c ^2 – b^2 / 2ac)

B = cos^-1(49 + 289 – √240 / 238)

B ≈ 75.685°.

A = 180 – B

A = 180 – 75.685

A = 24.315°

0.0016

reduce expression if possible by canceling the common factors

The first one , the second one ,the fourth one are true.

What is a commutative property in math?

This law simply states that with addition and multiplication of numbers, you can change the order of the numbers in the problem and it will not affect the answer.

1)  x + y = y + x  = a + c (b +  d ) i                                      true

2) ( xy )z = x (yz) = (a + bi)(c + di)( f + gi)                           true

3) x - y = a + bi - ( c - di ) = a - c + ( b- d )i

    y - x = c + di - ( a+bi) = c-a +(d-b)i                                  false

4) (x + y ) + z = x + ( y + z ) = a + c +f + (b +d + g)i                 true

5) (x - y ) - z = a + bi - ( c + di) - ( f + gi)

                    = a - c . f + ( b- d - g) i

         x - ( y - z ) = a + bi - ( c + di - f - gi )

                          = a - c + f + ( b - d + g ) i

{ put the hypothesis into the equation and get the proof }

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The amount saved in 10 years is = $1,04,461.13

The correct option is B.

An annuity is a series of payments that are distributed evenly over time.

One way to express the future value of an annuity of payment P for n years is,

Total salary is $65000

The interest rate is 5.32%

Trent save 8%  of his salary every year.

Company puts  4.6% of salary every year.

[tex]\text { Future Value }=\mathrm{P} \times \frac{\left(1+\frac{i}{n}\right)^{n t}}{\frac{i}{n}}[/tex]

Given:

Total salary is $65000

The interest rate is 5.32%

Trent save 8% of his salary every year.

Company puts  4.6%of salary every year.

The 8% of salary is calculated as:

[tex]\text { Amount } &=\frac{8}{100} \times 65000\\[/tex]

               [tex]&=\$ 5200[/tex]

The following information is available on the company's put:

[tex]\text { Amount } &=\frac{4.6}{100} \times 65000\\[/tex]

                [tex]&=\$ 2990[/tex]

Total amount as follows:

[tex]\begin{aligned}\text { Amount } &=5200+2990 \\&=\$ 8190\end{aligned}[/tex]

The future value can be obtained as follows

[tex]\begin{aligned}\mathrm{FV} &=8190 \times \frac{(1+0.053)^{10}-1}{0.053} \\&=8190 \times 12.75 \\&=1,04,461.13\ \\\end{aligned}[/tex]

Hence, the amount saved in 10 years is = $1,04,461.13

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Considering the dot plot, it is found that the tallest conifer is 3.25 inches taller than the shortest conifer.

It shows, with dots, the number of times that each of the measures appears in a data-set.

Researching this problem on the internet, and finding the dot plot, we have that:

The difference is:

9.5 - 6.25 = 3.25 inches.

Hence the tallest conifer is 3.25 inches taller than the shortest conifer.

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Answer:

There are two solutions:  
x = 0, y = -3  Point (0, -3)
x = 3, y = -6  Point (3, 6)

The solutions are at the intersections of the two individual graphs corresponding to each of the two equations (see attached figure)

Step-by-step explanation:

Use a graphing calculator or tool to plot each equation. The point of intersection of the two is the solution to the system of equations. See attached image

Algebraically

The first equation must be equal to the second equation for a unique value of y and x

[tex]y = x^2 - 3 = 3x -3\\x^2 - 3 = 3x - 3[/tex]

Subtract 3x - 3 from both sides giving

[tex]x^2 - 3 - (3x -3) = 0\\x^2 -3 -3x + 3 = 0\\x^2 - 3x = 0\\[/tex]

Factoring out x we get
[tex]x(x-3) = 0[/tex]

This means that x = 0 and also
x -3 = 0, or x = 3

Substituting for x = 0 in y = 3x-3 gives
y = 3.0 - 3 = -3
So x= 0, y = -3 is one solution (0,-3)

Substituting for x = 3 in the same equation gives
y = 3(3) - 3 = 6
So x = 3, y = 6 is another solution (3, 6)

Answer:

[tex]z=\frac{t^{2}(m-3) }{4}[/tex]    or    [tex]z=\frac{1}{4}t^{2} (m-3)[/tex]

Step-by-step explanation:

[tex]t=\sqrt{\frac{4z}{m-3} }[/tex]

[tex]t^{2} =\frac{4z}{m-3}[/tex]

[tex]4z=t^{2} (m-3)[/tex]

[tex]z=\frac{t^{2}(m-3) }{4}[/tex]

Hope this helps

Answer:

Connect the arcs to make a perpendicular bisector

The values that exist two standard deviations above and below the mean are 681 and 265.

The given parameters exist:

Mean = 473

Standard deviation =104

The values above and below the mean exist calculated utilizing:

[tex]$x=\bar{x} \pm n \sigma$[/tex]

In this case n = 2.

So, we have, [tex]$x=\bar{x} \pm 2 \sigma$[/tex]

The value above is:

x = 473 + 2 [tex]*[/tex] 104 = 681

The value below is:

x = 473 - 2 [tex]*[/tex] 104 = 265

Therefore, the values that exist two standard deviations above and below the mean are 681 and 265.

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The height of the cone in terms of y is h = 12x⁴y

The cylinder and the cone have the same volume.

Volume of a cylinder = πr²h

where

Therefore,

Volume of a cylinder = πx²y

volume of a cone = 1 / 3 πr²h

where

Therefore,

πx²y = 1 / 3 × π × (1 / 2x)² × h

πx²y = πh / 12x²

πx²y × 12x² / π = h

h = 12x⁴y

Therefore, the height of the cone in terms of y is h = 12x⁴y

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Answer:

200,075

Step-by-step explanation:

90 times 2.5 = 225

225 divided by 3 = 75

75 + 200,000 = 200,075

Answer: 200075

Step-by-step explanation:

90 * 2.5 = 225

225 / 3 = 75

75 + 200,000 = 200,075

Answer:

Step-by-step explanation:

A square is made up of 4 sides that are equal in length. They can all be called "x" or "s" or whatever variable you want. The formula for the area of a square (and also the area of a rectangle) is Area = side × side.

If you called your sides "x", then the formula is A = x × x or A = x². Another way to note the area of either a square or a rectangle is to call the "bottom" the base and one of the sides the height and then the area formula looks like this:

A = b × h

or

A = length × width

They are all the same thing.

x=-2

Step-by-step explanation:

Solution Given:

3(x-3) = 5(2x + 1)

Opening bracket we get

3x-9=10x+5

keeping common value in same side

-9-5=10x-3x

-14=7x

x=-14/7

x= -2

Answer:

-2 =x

Step-by-step explanation:

3(x-3) = 5(2x + 1)

To solve for x

Distribute

3x -9 = 10x +5

Subtract 3x from each side

3x-9-3x = 10x -3x+5

-9 = 7x+5

Subtract 5 from each side

-9-5 = 7x+5-5

-14 = 7x

Divide by 7

-14/7 = 7x/7

-2 =x

By substitution, the value of x and y are 1 and 1 respectively.

3 / 8 x + 1 /3  y = 17 / 24

x + 7y = 8

x = 8 - 7y

Let's substitute the value of x in equation(ii)

3 / 8(8 - 7y) + 1 / 3 y = 17 / 24

3 - 21 / 8 y + 1 / 3 y = 17 / 24

1 / 3 y - 21 / 8 y = 17 / 24 - 3

8y - 63y/24 =  17 - 72/ 24

-55y / 24 = -55 / 24

cross multiply

-1320y = -1320

divide both sides by -1320

y = -1320 / -1320

y = 1

Hence,

x + 7(1) = 8

x = 8 - 7

x = 1

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Answer:

  24 m depth

Step-by-step explanation:

The quadratic function modeling depth will have zeros at x=1 and x=12, the distances in meters from the boat where the diver is at the surface.

The factored form of a quadratic function can be written as ...

  y = a(x -p)(x -q)

where p and q are zeros of the function. The value 'a' is a vertical scale factor.

Here, we are given y=0 at the surface, at points where x=1 and x=12. This means the function can be written as ...

  y = a(x -1)(x -12)

To find the value of 'a', we can use the maximum depth value. That depth will be halfway between the function zeros, at x = (1+12)/2 = 6.5

  -30.25 = a(6.5 -1)(6.5 -12)

  30.25 = 5.5²·a = 30.25a   ⇒   a=1

Then the function modeling the diver's depth in meters is ...

  y = (x -1)(x -12)

And the depth at x=4 will be ...

  y = (4 -1)(4 -12) = 3(-8) = -24 . . . . meters

The diver's depth is 24 meters when she is 4 m away from the boat.

Based on the information given about the temperature, Daniela made her error on step 3 because it says: "Find the ratio of the differences of the means compared to the mean absolute deviation.

From the information given, it van be seen that Daniela recorded the low temperatures during the school day last week and this week and her results are shown in the table.

Here, she didn't find the difference between the today and last week means. She just put the mean as a whole.

Therefore, Daniela made her error on step 3 because it says: "Find the ratio of the differences of the means compared to the mean absolute deviation. This was the error.

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The equivalent expression to [tex](k o h)(x)[/tex]is [tex]\frac{1}{5 + x}[/tex]

Therefore  [tex](k o h)(x) = \frac{1}{5 + x}[/tex]

Given that the functions h is defined by h(x)=5+x

and k is defined by k (x) = [tex]\frac{1}{x}[/tex]

To find the composition of k and h that is: (k o h) (x)

Therefore

k (h(x)) = k (5+x)

k (h(x)) = [tex]\frac{1}{5+ x}[/tex]

The equivalent expression to is [tex]\frac{1}{5+ x}[/tex]

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