Answer:
$40
Step-by-step explanation:
we know that
The linear equation in slope intercept form i equal to
[tex]y=mx+b[/tex]
where
y is the amount of her mother's donation
x is the number of miles that Melissa walks
where
m is the slope
b is the y-intercept
In this problem
The slope is
[tex]m=\$2\ per\ mile[/tex]
The y-intercept is
[tex]b=\$10[/tex]
substitute
[tex]y=2x+10[/tex]
so
For x=15 miles
substitute
[tex]y=2(15)+10=\$40[/tex]