Упростите выражение: 1)а)(7а-1)2+14а б)12ab+(6a-b)2 в)(3а-b2)-9a2 г)4х2-(2х+1)2 (5a-1)2+10a (4+7x)2-56x 6ab+(3a-2b)2 49x2-(2-7x)2 в кводрате 

[latex](7a-1)^2+14a=49a^2-14a+1+14a=49a^2+1\12ab+(6a-b)^2=12ab+36a^2-12ab+b^2=36a^2+b^2\(3a-b)^2-9a^2=9a^2-6ab+b^2-9a^2=b^2-6ab\4x^2-(2x+1)^2=4x^2-4x^2-4x-1=-4x-1\(5a-1)^2+10a=25a^2-10a+1+10a=25a^2+1\(4+7x)^2-56x=16+56x+49x^2-56x=16+49x^2\6ab+(3a-2b)^2=6ab+9a^2-6ab+4b^2=9a^2+4b^2\49x^2-(2-7x)^2=49x^2-4+28x-49x^2=28x-4[/latex]