1.x：3.5=x-16:1.5
3.5(x-16)=1.5x
3.5x-3.5×16=1.5x
3.5x-1.5x=3.5×16
2x=3.5×1.6
x=3.5×0.8
x=2.8
2.x-20%x=3/4×40%
x-0.2=0.3
x=0.3+0.2
x=0.5
3.5.1x-1.7×3=30.6
5.1x-5.1=30.6
5.1x=30.6+5.1
5.1x=35.7
x=35.7÷5.1
x=7