2x—1.5x=75
解:0.5x=75
x=75/0.5
x=150
13X0.8–2x=4.9
解:2x=10.4-4.9
x=5.5/2
x=2.75
15.6➗4x=1.56
解:4x=15.6/1.56
x=10/4
x=2.5
10X(15–x)=12
解:150-10x=12
10x=150-12
x=138/10
x=13.8
32x—7x—5x=420
解:20x=420
x=420/20
x=21
1.4X5➕6x=11.2
解:6x=11.2-7
x=4.2/6
x=0.7
2x—1.5x=75 解:0.5x=75,x=150
13X0.8–2x=4.9 解:2x=5.5,x=2.75
15.6➗4x=1.56解:6.24x=15.6,x=2.5
10X(15–x)=12解:150-10x=12,10x=138,x=13.8
32x—7x—5x=420解:20x=420,x=21
1.4X5➕6x=11.2解:6x=4.2,x=0.7