Zadanie 2
a) 2x + (y - 6) - ( x - y) = 2x + y - 6 - x + y = x + 2y - 6
b) 4x - 7 - 3x + 7 = x
Zadanie 3
[tex]2x^2 - xy - 5x^2 + 2xy = -3x^2 + xy[/tex]
[tex]-3x^2 + xy = -3*(\frac{1}{3})^2 + \frac{1}{3}*9 = -3 + \frac{1}{9} + 3 = -\frac{1}{3} + 3 = -\frac{1}{3} - \frac{9}{3} = \frac{8}{3} = 2\frac{2}{3}[/tex]
