把X移到左边就变成了0.2x=50,然后除一下就可以算出x=250
1.2x=x+500.2x=50x=250
1.2x=x+501.2X-X=500.2X=50X=250
1.2x=x+501.2x-x=500.2x=50x=50÷0.2x=250