解方程 x+40%x=42 x-25%x=15 x-65%x=0.7 x+75%x=3.5
问题描述:
解方程 x+40%x=42 |
x-25%x=15 | x-65%x=0.7 | x+75%x=3.5 |
答
①x+40%x=42
1.4x=42
1.4x÷1.4=42÷1.4
x=30
②x-25%x=15
0.75x=15
0.75x÷0.75=15÷0.75
x=20
③x-65%x=0.7
0.35x=0.7
0.35x÷0.35=0.7÷0.35
x=2
④x+75%x=3.5
1.75x=3.5
1.75x÷1.75=3.5÷1.75
x=2