5X-15=30
5x=45
x=9
25*4+5X=120
5x=20
x=4
7*8-6X=38
6x=18
x=3
5X-3.6=2.4
5x=6
x=1.2
2X/5.6=1.2
x=1.2*2.8
x=3.36