Write 10:6 in the ratio 1:n A: 5:3 B: 1:1.6666 C: 1:4 D: 1:0.6

You purchase a stereo system for $830. The value of the stereo system decreases 13% each year. a. Write an exponential decay mod

lorasvet [3.4K]

Answer:

a. $y=830*(0.87)^x$

b. The value of stereo system after 2 years will be $628.23.

c. After approximately 4.98 years the stereo will be worth half the original value.

Step-by-step explanation:

Let x be the number of years.

We have been given that you purchased a stereo system for $830. The value of the stereo system decreases 13% each year.

a. Since we know that an exponential function is in form: $y=a*b^x$ , where,

a = Initial value,

b = For decay b is in form (1-r), where r is rate in decimal form.

Let us convert our given rate in decimal form.

$13\%=\frac{13}{100}=0.13$

Upon substituting our given values in exponential decay function we will get

$y=830*(1-0.13)^x$

$y=830*(0.87)^x$

Therefore, the exponential model $y=830*(0.87)^x$ represents the value of the stereo system in terms of the number of years since the purchase.

b. To find the value of stereo system after 2 years we will substitute x=2 in our model.

$y=830*(0.87)^2$

$y=830*0.7569$

$y=628.227\approx 628.23$

Therefore, the value of stereo system after 2 years will be $628.23.

c. The half of the original price will be $\frac{830}{2}=415$ .

Let us substitute y=415 in our model to find the time it will take the stereo to be worth half the original value.

$415=830*(0.87)^x$

Upon dividing both sides of our equation by 830 we will get,

$\frac{415}{830}=\frac{830*(0.87)^x}{830}$

$0.5=0.87^x$

Let us take natural log of both sides of our equation.

$ln(0.5)=ln(0.87^x)$

Using natural log property $ln(a^b)=b*ln(a)$ we will get,

$ln(0.5)=x*ln(0.87)$

$\frac{ln(0.5)}{ln(0.87)}=\frac{x*ln(0.87)}{ln(0.87)}$

$\frac{ln(0.5)}{ln(0.87)}=x$

$\frac{-0.6931471805599}{-0.139262067}=x$

$x=4.977286\approx 4.98$

Therefore, after approximately 4.98 years the stereo will be worth half the original value.

5 0

3 years ago

Equations that look different but have the same solution are said to be

Gekata [30.6K]

Let's define each choice to differentiate which is the answer

A. Equivalent - equivalent equations may not look exactly the same on face value. But they are equivalent because they have the same exact solution.

B. Expressions - expression is a general term for equations that are formed from word problems

C. Equal - equal equations are the exact duplicate of each other

D. Similar - this term is only used on geometric shapes to tell that the two shapes have a fixed ratio of their similar sides or angles

E. Radical - radical equations are those involving fractions

Therefore, from their descriptions, the answer is A.

3 0

3 years ago

A triangle has side lengths of (8s + 8) centimeters, (s +9) centimeters, and

quester [9]

Answer:

Step-by-step explanation:

(16.2t+3.4u+2.9)cm

Step-by-step explanation:

A triangle is a plane shape that has three sides. The perimeter of a triangle is gotten by taking the sum of all the lengths of the three sides. Let the length of the three sides by s1, s2 and s3, the perimeter of the triangle will be expressed as;

P = s1+s2+s3

Given the side lengths

s1 = (8.1t-6.1)cm

s2 = (8.1t+7.1)cm

s3 = (3.4u+1.9)cm

Perimeter of the triangle = 8.1t-6.1+8.1t+7.1+3.4u+1.9

collect the like terms

P = 8.1t+8.1t+3.4u-6.1+7.1+1.9

P = 16.2t+3.4u+2.9

Hence the expression that represents the perimeter, in centimeters, of the triangle is (16.2t+3.4u+2.9)cm

5 0

2 years ago

Anyone! Please help me! I don't understand at all what to do! Help would be really appreciated :)

Rom4ik [11]

Answer: They are parallel

Step-by-step explanation:

If two lines are parallel , then they must have the same slope and if two lines are perpendicular , the product of their slope must be -1.

To check this , we must calculate the slope of the two lines given.

Slope = $\frac{y_{2}-y_{1}}{x_{2}-x_{1}}$

from the first point

$y_{1}$ = 2

$y_{2}$ = 1

$x_{1}$ = 5

$x_{2}$ = -1

substituting the values

slope 1 = 1 - 2 / -3 - 5

slope1 = -1 / -8

slope 1 = 1/8

Using the same format to calculate the slope of the second line

$y_{1}$ = -2

$y_{2}$ = 0

$x_{1}$ = -1

$x_{2}$ = 15

slope 2 = 0 - (-2) / 15 - (-1)

slope 2 = 2/16

slope 2 = 1/8

Since slope 1 = slope 2 , this implies that the lines are parallel

6 0

3 years ago

Write the standard form of the line that passes through the given points. Include your work in your final answer. Type your answ

alexandr402 [8]

-2 -3 / 3 - 1

-5 / 2

So the slope of the points is -5/2, and I have no explanation other than I used to point slope formula.

5 0

3 years ago

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