Odpowiedź:
a) (x+1)(x+2)=x²+2x+x+2=x²+3x+2
b) (3a+4)(a-5)=3a²-15a+4a-20=3a²-11a-20
c) (2t+1)(1-3t)=2t-6t²+1-3t=-6t²-t+1
d) (3ab-7)(3-7ab)=6ab-21a²b²-21+49ab=-21a²b²+58ab-21
e) (-x+y)(5x+6y)=-5x²-6xy+5xy+6y²=-5x²+6y²-xy
f) (x+5)(7x-y)=7x²-xy+35x-5y
g) (2x-y)(x+y)=2x²+2xy-xy-y²2x²+xy-y²
h) (ab-a)(2ab+6a)=2a²b²+6a²b-2a²b-6a²=2a²b²+4a²b-6a²
Szczegółowe wyjaśnienie:
