2(a-1)^2+3(a-2)^2
4(m-2n)^2-3(3m+n)^2
4(3x+4y)^2-7(2x-3y)^2
5(n-5m)^2-6(2n-3m)^2-(3m-n)*(7m-n)
Спасибо)2a^2-4a+2+3a^2-12a+12=5a^2-16a+14;
4m^2-16mn+16n^2-27m^2-18mn-3n^2=
=-23m^2-34mn+12n^2;
36x^2+96xy+64y^2-28x^2+84xy-63y^2=
=8x^2+180xy+y^2;
5n^2-50nm+125m^2-24n^2+72nm-54m^2-
-(21m^2-3mn-7mn+n^2)=-24m^2+22mn+71n^2-21m^2+10mn-n^2=-45m^2+32mn+70n^2.