Answer :
The linear equation for the number of cookies he receives, for x hours practicing the piano, is:
[tex]y = x + 10[/tex]
A linear function has the format given by:
[tex]y = mx + b[/tex]
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:
[tex]m = \frac{20 - 15}{10 - 5} = \frac{5}{5} = 1[/tex]
Then
[tex]y = x + b[/tex]
Point (5,15) means that when [tex]x = 5, y = 15[/tex], which is used to find b.
[tex]15 = 5 + b[/tex]
[tex]b = 10[/tex]
The, the function is:
[tex]y = x + 10[/tex]
A similar problem is given at https://brainly.com/question/16302622