Question

A college student completed some courses worth 3 credits and some courses worth 4 credits. The student earned a total of 59 credits after completing 18 courses. How many courses worth 3 credits did the student complete?

Answer 1

They completed 13, 3 credit classes

Explanation:

1. Make 2 formulas. In this case: x+y=18

and 3x+4y=59

2. Then multiply x+y=18 by 3 and subtract the two equations.

Find y which is 5 and input into the equations. Then find your answer.