Word problems with three unknowns using a linear equation

Question

over the last 3 evenings, Jina recived a total of 83 phone calls at the center. the third evening, she recevied 2 times as many calls as the first evening. the second evening, she receivied 5 fewer calls than the first evening. How many phone calls did she recieve each evening?

Answer 1

T=2F

S=F-5

F+S+T = 83

F+ F-5 + 2F = 83

4F = 88

F = 88/4 = 22 calls the first evening

S = 22-5 = 17 calls the 2nd evening

T= 2(22) = 44 calls the third evening