Trevor pays $125 in fees each semester plus $650 per college course.

Last semester Trevor paid $2,725.

Which function represents Trevor's bill?

A. f (x) = 125x + 650

B. f (x) = 650x + 125

C. f (x) = 775x

D. f (x) = 525x

The correct answer is Choice B.

This is an example of an equation in slope-intercept form, y = mx + b.

The slope, m, is the amount of increase each course, or 650.

The y-intercept, b, is the starting fees that are paid.

Put them together and you have: y = 650x + 125 of Choice B.