(1)40%x+1.2=4.8,
40%x+1.2-1.2=4.8-1.2,
40%x=3.6,
40%x÷40%=3.6÷40%,
x=9;
(2)X:12=0.7:2.8,
2.8X=12×0.7,
2.8X=8.4,
2.8X÷2.8=8.4÷2.8,
X=3;
(3)
x
4 =
3.5
1.5 ,
1.5x=3.5×4,
1.5x=14,
1.5x÷1.5=14÷1.5,
x=9
1
3 .
(1)40%x+1.2=4.8,
40%x+1.2-1.2=4.8-1.2,
40%x=3.6,
40%x÷40%=3.6÷40%,
x=9;
(2)X:12=0.7:2.8,
2.8X=12×0.7,
2.8X=8.4,
2.8X÷2.8=8.4÷2.8,
X=3;
(3)
x
4 =
3.5
1.5 ,
1.5x=3.5×4,
1.5x=14,
1.5x÷1.5=14÷1.5,
x=9
1
3 .