4
a) 7+3x=2(4-x)
7+3x=8-2x
3x+2x=8-7
5x=1 |:5
x=0,2
b) 4(6-x)=2(x-3)
24-4x=2x-6
24+6=2x+4x
30=6x
6x=30 |:6
x=5
5
a) 5(x-7)+2= -28
5x-35+2= -28
5x= -28+35-2
5x=5 |:5
x=1
b) 2(x-1)+3(x+1)=26
2x-2+3x+3=26
2x+3x=26+2-3
5x=25 |:5
