0.1*0.7+5x=五分之四 3.2*5-80%x=2 0.4（x-二分之一）=2.4
0.07+5x=0.8 16-0.8x=2 0.4x-0.2 =2.4
5x=0.73 -0.8x=-14 0.4x=2.6
x=0.146 x=17.5 x=6.5
x+四分之一=0.6*150%
x+0.25=0.9
x =0.65