So in slope intercept form or y=mx+b or in your case c=mx+b where b=15, x=number of movies and b=2 dollars per cd then
C=2x+15 so
the C intercept is when x=0 so
set x to 0 and get
2(0)+15=C
0+15=C
C=15
Cintercept=15
slope=m so slope=2
C intercetp=15
so if borrow certain number of movies just plug in the values for x so
1
2(1)+15=2+15=17
2
2(2)+15=4+15=19
and so on
