1.3×35%+8.7÷七分之二十=1.3 x0.35 +8.7 x7/20 =1.3 x0.35+8.7x0.35 =0.35 x (1.3+8.7) =0.35 x10 =3.5 解方程： 0.25+25%x=1.50.25+0.25x=1.5 0.25x=1.25 x=5 x-20%x=400.8x=40 x=50 x+60%x=五分之八 1.6x=5/8 x=5/8*5/8 x=25/64
采纳哦