Is it proportional and what’s the solution?

Solve the problem. a student earned grades of c, a, b, and a in four different courses. those courses had these corresponding numbers of credit hours: 4, 5, 1, and 5. the grading system assigns quality points to letter grades as follows: a = 4, b = 3, c = 2, d = 1, and f = 0. compute the grade point average (gpa) and round the result to two decimal places. 3.40 3.50 8.75 2.18

What is the measure of ac? 5 units 13 units 26 units 39 units 3x- 2b 6x + 9

Need showing work for this problem 56.25 ×25.80