զ) 4(a-2b)2-9(2a-b)2=4(a2-4ab+4b2)-9(4a2-4ab+b2)=4a2-16ab+16b2-36a2+36ab-9b2=-32a2+20ab+7b2
է) 3(2-3m)2-3(2-3m)(3m+2)=3(4-12m+9m2)-3(6m+4-9m2-6m)=12-36m+27m2-12+27m2=-36m+54m2
ը) 2(1-5x)2-2(5x+1)(1-5x)=2(1-10x+25x2)-2(5x-25x2+1-5x)=2-20x+50x2-10x+50x2-2+10x=-20x+100x2
բ) a3-3ab(a-b)-b3=(a-b)3
a3-3a2b+3ab2-b3=(a-b)3
(a-b)3=(a-b)3
բ) (a-b)2+4ab=a2-2ab+b2+4ab=a2+2ab+b2=(a+b)2
դ) (x-3y)2+12xy=x2-6xy+9y2+12xy=x2+6xy+9y2=(x+3y)2
Նանե Խաչատրյան 