4+x=72 (x+15)/3*6=48
x=72-4 2(x+15)=48
x=68 x+15=48:2
x+15=24
x=24-15
x=9
4+x=72 x/5+3=8
x=68 x/5=5
x=25
4+x=72 (x+15)/3*6=48
x=72-4 2(x+15)=48
x=68 x+15=48:2
x+15=24
x=24-15
x=9
4+x=72 x/5+3=8
x=68 x/5=5
x=25