1.3x + 1.2 =4.5
3x=3.3
x=1.1
2.1/2:1/3 =1/4:x
1/2x=1/3×1/4
1/2x=1/12
x=1/6
3.3/4x - 2 =1.6
3/4x=3.6
x=4.8
4.(0.4+x)×6 = 5.4
0.4+x=0.9
x=0.5