七份之四X+(90—X)乘三份之二=56 怎么解方程?计算过程也要写出来
问题描述:
七份之四X+(90—X)乘三份之二=56 怎么解方程?计算过程也要写出来
答
(4/7)x+(90-x)*(2/3)=56
(4/7)x+60-(2/3)x=56
(4/7)x-(2/3)x=-4
(-2/21)x=-4
2x=4*21
x=42