3(y-3)-5(1+y)=7(y-1) 一元一次方程如何解
问题描述：
3(y-3)-5(1+y)=7(y-1) 一元一次方程如何解
答
3y-9-5-5y=7y-7
3y-5y-7y=9+5-7
-9y=7
y=-7/9
答
(3y-9)-(5+5y)=7y-7
3y-9-5-5y=7y-7
-2y-9-5=7y-7
-9y=7
y=-7/9
答
3y-9-5-5y=7y-7
7y+5y-3y=-5-5+7
9y=-3
y=-1/3
答
3y-9-5-5y=7y-7
7y+5y-3y=-9-5+7
9y=-7
y=-7/9