Odpowiedź :
[tex]a) \ -4x-7-3x+7 = -7x\\\\b) \ x - 2xy + \frac{1}{2}x - \frac{1}{3}xy = 1\frac{1}{2}x -2\frac{1}{3}xy\\\\c) \ -x^{2} +y^{2}-2x^{2}-2y^{2} = -3x^{2}-y^{2}\\\\d) \ -x^{2}+2x-3x+x^{2} = -x\\\\e) \ 4x+4-7x-\frac{1}{2} = -3x+3\frac{1}{2}[/tex]