Question

8th grade math

Write an equation that models each situation in slope-intercept form by finding the slope and y-intercept

Emma started with some money from her birthday and then saved the same amount from her allowance each week. After 4 weeks of saving, Emma had $32. After 8 weeks of saving she has $42.

Answer 1

y = 2.5x + 22

Explanation:

the two points are (4,32) and (8,42)

The slope would be

`(42 - 32)/(8-4)` =
`(10)/(4)` =
`(5)/(2)` = 2.5

This is the slope. She saves $2.50 per week.

the y-intercept is how much money she started with

Use one point. I will us (4,32) and the slope (2.5)

y = 32

m = 2.5

x = 4

y = mx + b

32 = 2.5(4) + b

32 = 10 + b Subtract 10 from both sides

22 = b

This is the y-intercept. This is how much money she had in the beginning.

y =mx + b

y = 2.5x + 22