这题怎么做 3.5x-2.5=8 4x3*7=29 5x+5*7=68 5x-3*11=42 7x-5*0.5=57.7

3.5x-2.5=8
3.5x=8+2.5
3.5x=10.5
x=3
4x+3*7=29
4x=29-21
4x=8
x=2
5x+5*7=68
5x=68-35
5x=33
x=6.6
5x-3*11=42
5x=42+33
5x=75
x=15
7x-5*0.5=57.7
7x=57.7+2.5
7x=60.2
x=8.6