90-X=(180-X)2/3-40解此方程,过程!
问题描述:
90-X=(180-X)2/3-40解此方程,过程!
答
90-X=(180-X)2/3-40
90-x=120-2x/3-40
1/3x=10
x=30
答
90-X=(180-X)2/3-40
两边乘以3;270-3x=360-2x-120
-3x+2x=240-270
-x=-30
x=30