Question

a : b = 7 rest 4
a - b = 124

Answer 1

a:b=7, rest 4=>a=7b+4
a-b=124
7b+4-b=124
6b+4=124
6b=120
b=20
a-b=124
a=20=124
a=144

Answer 2

a-b=124
a:b=7+r4          a=7b+4
7b+4-b=124
6b=124-4
b=120:6
b=20
a=7*20+4=140+4=144
a=144
144-20=124 proba