Question

Помогите решить!!!!!!!!

Answer 1

$1);(7a-1)^2+14a=49a^2-14a+1+14a=49a^2+1\2);12ab+(6a-b)^2=12ab+36a^2-12ab+b^2=36a^2+b^2\3);49x^2-(2-7x)^2=49x^2-4+28x-49x^2=28x-4\4);(5a-1)^2+(a+5)^2=25a^2-10a+1+a^2+10a+25=26a^2+26\5);4a(5a+2)+7a(3a-4)=20a^2+8a+21a^2-28a=41a^2-20a$