Question

Номера 259 и 260, помогите, пожалуйста.

Answer 1

(a-6b)²(a+6b)=(a-6b)(a-6b)(a+6b)=(a²-6ab-6ab+36b²)(a+6b)=
=(a+6b)(a²-12ab+36b²)=a³-12a²b+36ab²+6a²b-72ab²+216b³=
=a³-6a²b-36ab²+216b³

4a-2(a+1)²        a=√5
4a-2(a+1)(a+1)=4a-2(a²+a+a+1)=4a-2a²-4a-2=-2a²-2=
=-2*5-2=-10-2=-12