(x-8)*0.3=5.7
X-8=19
X=27
8x/7=12
8X=84
X=21/2
X=10.5
3(7x+8x-13x)=114
2X=38
X=19
6.5x-3.7-2.8=6.5
6.5X=6.5+6.5
X=2