a)
3(1-x)+2=-7
3-3x+2=-7
-3x+5=-7
-3x=-7-5
-3x=-12 |:(-3)
x=4
b)
(x+3)/2-2x=4 |·2
x+3-4x=8
x-4x=8-3
-3x=5|:(-3)
x=-5/3
c)
7(x+1)=6x-7
7x+7=6x-7
7x-6x=-7-7
x=-14
d(
(6x-4)(x+1)=6x²-10
6x²+6x-4x-4=6x²-10
6x-4x=-10+4
2x=-6|:2
x=-3
