解方程:x-1/2x=42 x-2/5x=3/8 x+0.8x=36 45-1/2x=5

问题描述:

解方程:x-1/2x=42 x-2/5x=3/8 x+0.8x=36 45-1/2x=5

x-1/2x=42
1/2x=42
x=84
x-2/5x=3/8
3/5x=3/8
x=3/8÷3/5
x=5/8
x+0.8x=36
1.8x=36
x=20
45-1/2x=5
1/2x=45-5
1/2x=40
x=80
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