5t + 15s = 211.25
t = s + 15.25
Substitute the second equation into the first equation for the t.
5(s + 15.25) + 15s = 211.25
Distribute the 5
5s + 76.25 + 15s = 211.25
20s + 76.25 = 211.25
Subtract 76.25 from both sides
20s = 135.00
Divide both sides by 10
s = 6.75
t = 6.75 + 15.25
t = 22.00
CHECK
5t + 15s ?=? 211.25
5(22.00) + 15(6.75) =
$ 211.25
