dam max, bardzo wazne na teraz

Odpowiedź:
-4x - 7-3x+7= - 7x
[tex] - {x}^{2} + 2x - 3x + 4 {x}^{2} = 3 {x}^{2} - 1x[/tex]
[tex]2 {x}^{2} - xy - 5 {x}^{2} + 5xy = - 3 {x}^{2} + 4xy[/tex]
(a + b) - (2a- B) - (a - 2b)= a+b-2a+b-a+2b= - 2a+ 4b