Odpowiedź:
Z.1
Odp. B
Z.2
[tex]10x^{2} + 8[/tex]
Szczegółowe wyjaśnienie:
Z.1
[tex](3x+4)(5-x) = 15x-3x^{2} + 20 - 4x = 11x - 3x^{2} + 20[/tex]
Odp. B
Z.2
Podzielmy to na 4 figury.
[tex]P1 = 4x*5x = 20x^{2}[/tex]
[tex]P2 = \frac{5x*4x}{2} = \frac{20x^{2} }{2} = 10x^{2}[/tex]
[tex]P3 = \frac{4*4}{2} = \frac{16}{2} = 8[/tex]
[tex]P4 = P1 - (P2+P3)\\P4 = 20x^{2} - (10x^{2} - 8)\\P4 = 20x^{2} - 10x^{2} + 8\\P4 = 10x^{2} +8[/tex]
