Răspuns:
a)x+x+3+x+1=34
3x=30
x=10
x+1=11
x+3=13
b)2(x+2+x)=16
4x+4=16
4x=12
x=3
x+2=5
c)x+x+20=90
2x=70
x=35
x+20=55
