Question

Colin loves to play the piano but doesn't like practicing the exercises his piano teacher assigns. Colin
knows the exercises will help him play better though, so he tries to motivate himself using his favorite
treat-chocolate chip cookies.
There is a proportional relationship between the amount of time (in hours) that Colin practices the
piano, x, and how many cookies he gives himself, y.
x (hours) y (cookies)
5
10
A WNH
15
20

Answer 1

The linear equation for the number of cookies he receives, for x hours practicing the piano, is:

$y = x + 10$

A linear function has the format given by:

$y = mx + b$

In which:

• m is the slope, which is the rate of change.
• b is the y-intercept, which is the value of y when x = 0.

In this problem:

• We have two points: (5,15) and (10,20).
• The slope is given by change in y divided by change in x, then:

$m = \frac{20 - 15}{10 - 5} = \frac{5}{5} = 1$

Then

$y = x + b$

Point (5,15) means that when $x = 5, y = 15$, which is used to find b.

$15 = 5 + b$

$b = 10$

The, the function is:

$y = x + 10$

A similar problem is given at https://brainly.com/question/16302622