a)
2x-4=3+x
2x-x=3+4
x=7
b)
5x-4-4x=2x-3+3
5x-4x-2x-3x=-3+4
-5x=1/-5
x=-5
c)
3(4x+3)=4x+15
12x-9=4x+15
12x-4x=15-9
8x=6
x=6/8
x=[mat]\frac{6}{8}[/mat]
d)
9-3(2x-1)=0
6x=-9-3
6x=-6
x=-6/6
x=-1
e)3x-5=2x-1
3x-2x=2x-1
3x-2x=-1+5
x=4/1
x=4
f)
2-3x+5=x-5-7x
-3x-x+7x=-5-5-2
-4x+7x+=-12
-3x=-12/-3
x=4