解方程要带过程!7x-25=13.54x-2x=3*1812(2+3x)=42x-0.2x=5.22/5x-1/8=3/4x-15%x=8.5x+7/9x=4/34/5x-2/3x=242/3x+50%x=4.2还有解比例--x比28=1:41比5:0.5=3:x25比

Question

解方程 要带过程!
7x-25=13.5 4x-2x=3*18 12(2+3x)=42 x-0.2x=5.2 2/5x-1/8=3/4 x-15%x=8.5
x+7/9x=4/3 4/5x-2/3x=24 2/3x+50%x=4.2
还有解比例- - x比28=1:4 1比5:0.5=3:x 25比x=12.5比4.2 1/5:0.5=3比x
1/4:1/12=16:x

Answer 1

7x-25=13.5
7x=13.5+25
7x=38.5
x=38.5÷7
x=5.5
4x-2x=3*18
2x=3*18
x=3*18/2
x=27
12（2+3x）=42
2+3x=42/12
2+3x=7/2
3x=7/2-2
3x=3/2
x=3/2÷3
x=1/2
x-0.2x=5.2
0.8x=5.2
x=5.2/0.8
x=6.5
2/5x-1/8=3/4
2/5x=3/4+1/8
2/5x=7/8
x=7/8÷2/5
x=35/16
x-15%x=8.5
85%x=8.5
x=8.5/85%
x=10
x+7/9x=4/3
16/9x=4/3
x=4/3÷16/9
x=3/4
4/5x-2/3x=24
2/15x=24
x=24÷2/15
x=180
2/3x+50%x=4.2
2/3x+1/2x=21/5
7/6x=21/5
x=21/5÷7/6
x=18/5