解(1)1.6×(5-X)=3.2, 1.6×5-1.6x=3.2, 8-1.6x=3.2, 8-1.6x+1.6x=3.2+1.6x, 3.2+1.6x=8, 3.2+1.6x-3.2=8-3.2, 1.6x÷1.6=4.8÷1.6, x=3; (2)12-3X=4.8, 12-3x-4.8=4.8-4.8, 7.2-3x=0, 7.2-3x+3x=0+3x, 3x=7.2, 3x÷3=7.2÷3, x=2.4; (3)0.8X+0.5×13=10.5, 0.8x+6.5=10.5, 0.8x+6.5-6.5=10.5-6.5, 0.8x=4, 0.8x÷08=4÷0.8, x=5. |