b) 3x+5=20
3x=20-5
3x=15
x=15:3
x=5
c)13-2x=5
2x=13-5
2x=8
x=8:2
x=4
d)50-4x=11-5
50-4x=6
4x=50-6
4x=44
x=44:4
x=11
e)4(x-9)=4
4x-4*9=4
4x-36=4
4x=4+36
4x=40
. x=40:4
x=10
f)6(x+1)-10=29-3
6*x+6*1-10=26
6x+6-10=26
6x+6=26+10
6x+6=36
6x=36-6
6x=30
x=30:6
x=5
Sper ca ti-am fost de folos!