Odpowiedź :
(X+5)(2x+2)= 2x2+2x+10x+10=2x2+12x+10
(3X-y)(x+2y)=3x2+6xy-xy-2y2=3x2-2y2+5xy
(A+b)(5a-8b)=5a2-8ab+5ab-8b2=5a2-8b2-3ab
(2k-3m)(m-k)=2km+2k2-3m2-3km=2k2-3m2-km
(2a-b)(2a+b)=4a2+2ab-2ab-b2=4a2-b2
(3X-y)(x+2y)=3x2+6xy-xy-2y2=3x2-2y2+5xy
(A+b)(5a-8b)=5a2-8ab+5ab-8b2=5a2-8b2-3ab
(2k-3m)(m-k)=2km+2k2-3m2-3km=2k2-3m2-km
(2a-b)(2a+b)=4a2+2ab-2ab-b2=4a2-b2