3/5x-1/6=2/3 2x+0.8=4 0.4x(x-1.2)=1.2 10/9x-1/3x=21 3/4x-1/2=1/4 5(x-2.8)=140 x-3/7x=8/213/5x-1/6=2/3 2x+0.8=40.4x(x-1.2)=1.210/9x-1/3x=213/4x-1/2=1/4 5(x-2.8)=140x-3/7x=8/21方程和计算

3/5x-1/6=2/3 2x+0.8=4 0.4x(x-1.2)=1.2 10/9x-1/3x=21 3/4x-1/2=1/4 5(x-2.8)=140 x-3/7x=8/213/5x-1/6=2/3 2x+0.8=40.4x(x-1.2)=1.210/9x-1/3x=213/4x-1/2=1/4 5(x-2.8)=140x-3/7x=8/21方程和计算
3/5x-1/6=2/3 2x+0.8=4 0.4x(x-1.2)=1.2 10/9x-1/3x=21 3/4x-1/2=1/4 5(x-2.8)=140 x-3/7x=8/21
3/5x-1/6=2/3
2x+0.8=4
0.4x(x-1.2)=1.2
10/9x-1/3x=21
3/4x-1/2=1/4
5(x-2.8)=140
x-3/7x=8/21
方程和计算

3/5x-1/6=2/3 2x+0.8=4 0.4x(x-1.2)=1.2 10/9x-1/3x=21 3/4x-1/2=1/4 5(x-2.8)=140 x-3/7x=8/213/5x-1/6=2/3 2x+0.8=40.4x(x-1.2)=1.210/9x-1/3x=213/4x-1/2=1/4 5(x-2.8)=140x-3/7x=8/21方程和计算
3/5x-1/6=2/3 2x+0.8=4
3/5x-1/6+1/6=2/3 +1/6 2x=4-0.8
3/5x=2/3 +1/6 x=1.6
3/5x=5/6
3/5x÷3/5=5/6÷3/5
x=1/2
0.4x(x-1.2)=1.2
x-1.2=3
x=3+1.2
x=4.2
10/9x-1/3x=21
x=21x9/7
x=27
3/4x-1/2=1/4
3/4x-1/2+1/2=1/4+1/2
3/4x=3/4
x=1
5(x-2.8)=140
x-2.8=140÷5
x-2.8=28
x=30.8
x-3/7x=8/21
4/7x=8/21
4/7x÷4/7=8/21÷4/7
x=2/3

这是很基本的解方程啊，这个要是做不来，你以后的数学打算怎么办？

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