解一元一次方程:(1)3x-(2x-7)=-1 (2)7x-2(x-1)=-3 (3)2(3-y)-3(2/3y+1)=1
问题描述:
解一元一次方程:(1)3x-(2x-7)=-1 (2)7x-2(x-1)=-3 (3)2(3-y)-3(2/3y+1)=1
(4)9(2/3x+1)-2(x-1/2)=-2
答
(1)3x-(2x-7)=-1
3x-2x+7=-1
x=-8
(2)7x-2(x-1)=-3
7x-2x+2=-3
5x=-5
x=-1
(3)2(3-y)-3(2y/3+1)=1
6-2y-2y-3=1
-4y=-2
y=1/2
(4)9(2x/3+1)-2(x-1/2)=-2
6x+9-2x+1=-2
4x=-12
x=-3