You want to buy an MP3 player. Your Aunt paid you $20 to mow her lawn and you earn $5 each week 1. Write an equation in Slope-Intercept form that represents y total amount saved and

x is number of weeks
y=125x+5
y=20x+125
y=5x+20

2. Interpret the y-intercept
$5 the amount you start with before mowing lawns
$20 the amount you saved mowing your aunt's lawn
$125 the amount you need to earn

3. If the MP3 player costs $125, how many weeks until you can afford to buy it?
21 weeks
105 weeks
25 weeks

1. y = 5x + 20

2. $20 the amount you saved mowing your aunt's lawn.

3. 21 weeks

Step-by-step explanation:

1. 5 is the slope because it is the rate. 20 is the y-intercept because that is how much you already have.

2. 20 because that is how much you already have.

3. Since you already have $20, you need to subtract 125 by 20 to get 105. Then you divide 105 by 5 to get 21 weeks.

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places