解方程． 5x+28=71 8.7-1.2x=3.9 8x-2.6x=37.80.75x-0.95×4=8.5 2（x-3）=5.8 8x-2.6=37.8
问题描述：
| 解方程． 5x+28=71 |
8.7-1.2x=3.9 | 8x-2.6x=37.8 |
| 0.75x-0.95×4=8.5 | 2（x-3）=5.8 | 8x-2.6=37.8 |
答
①5x+28=71
5x+28-28=71-28
5x=43
5x÷5=43÷5
x=8.6
②8.7-1.2x=3.9
8.7-1.2x+1.2x=3.9+1.2x
8.7=3.9+1.2x
3.9+1.2x-3.9=8.7-3.9
1.2x=4.8
1.2x÷1.2=4.8÷1.2
x=4
③8x-2.6x=37.8
5.4x=37.8
5.4x÷5.4=37.8÷5.4
x=7
④0.75x-0.95×4=8.5
0.75x-3.8=8.5
0.75x-3.8+3.8=8.5+3.8
0.75x=12.3
0.75x÷0.75=12.3÷0.75
x=16.4
⑤2（x-3）=5.8
2（x-3）÷2=5.8÷2
x-3=2.9
x-3+3=2.9+3
x=5.9
⑥8x-2.6=37.8
8x-2.6+2.6=37.8+2.6
8x=40.4
8x÷8=40.4÷8
x=5.05