Question

(a-2b-3c)^2 раскройте скобки

Answer 1

$=(a-2b-3c)(a-2b-3c)= a^{2}-2ab-3ac+4 b^{2}+6bc-3ac+6bc+$

+$9 c^{2}= a^{2}+4 b^{2}+9 c^{2} -2ab-6ac+12bc$

Answer 2

(a-2b-3c)^2=(a-2b-3c)(a-2b-3c)=a(a-2b-3c)-2b(a-2b-3c)-3c(a-2b-3c)=a^2-2ab-3ac-2ab+4b^2+6bc-3ac+6bc+9c^2=a^2-4ab-6ac+12bc+4b^2+9c^2