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
第一个对
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
答
七份之四X+（90—X）乘三份之二=56
即： (4/7)x + (90-x) * (2/3)=56
(4/7)x + 60 - (2/3) x = 56
(2/3)x - (4/7)x = 4
2/21x = 4
x = 4 * 21/2 =42
答
解
4/7x+(90-x)x2/3=96
4/7x+60-2/3X=96
4/7X-2/3X=36
(4/7-2/3)x=36
方程各边乘以21
(12-14)x=36x21
-2x=36x21
x=-18x21
x=-378
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