plssss na teraz tylko podpunkt a i b daje naj

a)
[tex]\frac{x+1}{3} = 7 | *3\\\\x+1 = 21\\x = 21 - 1\\x = 20[/tex]
b)
[tex]\frac{3-x}{2} =\frac{1}{3} | *6\\9-3x=2\\-3x = 2-9\\-3x = -7 | /(-3)\\x = 2 \frac{1}{3}[/tex]