zad.5
2x-1+2x+2x+1+2x+2+2x+3=10x+5
zad.6
[tex]x + \frac{1}{4} x + \frac{1}{4} x + 1 = 1 \frac{1}{2} x + 1[/tex]
zad.7
2b-1+a+5+3b-7+2a+3+3b-7+3b-1+2a+3+b+a+5=6a+12b
