2[(60-x)÷60]=1×[(120-x)÷120]
问题描述：
2[(60-x)÷60]=1×[(120-x)÷120]
答
x=40
答
2[(60-x)÷60]=1×[(120-x)÷120]
[(60-x)÷30]=[(120-x)÷120]
120×[(60-x)÷60]=120×[(120-x)÷120]
2×(60-x)=(120-x)
120-2x=120-x
-2x+x=120-120
x=0
答
等式两边同时乘以120
2*2(60-x)=1*(120-x)
去括弧
240-4x=120-x
-4x+x=120-240
-3x=-120
x=40
答
X=40
答
2[(60-x)÷60]=1×[(120-x)÷120] 两边乘120
4（60-x）=120-x
240-4x=120-x
4x-x=240-120
3x=120
x=40