Odpowiedź:
zad. 1.
2a(3b - 4a) - 3b(a-2b) = 6ab - 8a² - 3ab + 6b² = -8a² + 3ab - 6b²
Odp. C
zad.2
14x²y - 42xy - 7xy² = 7xy (2x - 6 -1y)
Odp. D
zad. 3
2(x + y) - 5(x + y) + 4(x + y) = (2 - 5 + 4) (x + y) = 1 (x + y ) = x + y
(2x - 3)(2x + 3) = (2x)² - 3² = 4x² - 9
zad. 4
[tex]\frac{4x - 12}{4} - \frac{2x - 4}{2} = \frac{4x - 12}{4} - \frac{4x - 8}{4} = \frac{4x - 12 - 4x + 8}{4} = -\frac{4}{4} = - 1[/tex]
