I need help asap

Question

David the trainer has two solo workout plans that he offers his clients: Plan A and Plan B. Each client does either one or the other (not both). On Monday there were 12

 clients who did Plan A and 2

 who did Plan B. On Tuesday there were 3

 clients who did Plan A and 5

 who did Plan B. David trained his Monday clients for a total of 9

 hours and his Tuesday clients for a total of 9

 hours. How long does each of the workout plans last?

Answer 1

12A + 2B = 9

3A +5B = 9

multiply both sides by 4 to get

12A +20B =36

subtract 1st equation from the last to elminate one variable

18B = 36-9= 27

divide both sides by 18

B = 27/18 = 3/2 = 1.5 hours per Plan B workout

3A =9-5B = 9-5(1.5) = 9-7.5 = 1.5

A = 1.5/3 = .5 = 1/2 hour for Plan A workout

Plan B 1 1/2 hours

Plan A half an hour