one number is five more than another and there sum is three less than three times the smaller. find the number?
A is the number
B is the number
A = B+5 →call this eq1
A + B = 3(B) - 3 ← call this eq2
substitute eq1 to eq2
(B + 5) + B = 3(B) - 3
2B + 5 = 3B - 3
3B - 2B = 5 + 3
B = 8
Substitute B=8 to eq1
A = B+5 →call this eq1
A = 8 + 5
A = 13