(a-b)^2+(a+b)^2
=(a^2-2ab+b^2)+(a^2+2ab+^2)
=2a^2+2b^2
(x+y-5)^2+(x-y+3)^2
=((x-1)+(4-y))^2+((x-1)-(4-y))^2
=2(x-1)^2+2(4-y)^2
=2x^2-4x+2y^2-16y+36再来两道，快回答后多给你5分嗯(2a-b)^2(4a^2+b^2)^2(2a+b)^2 (5x+7y-3)(5x-7y+3)(2a-b)^2(4a^2+b^2)^2(2a+b)^2=(2a-b)^2*(2a+b)^2*(4a^2+b^2)^2=(4a^2-b^2)^2*(4a^2+b^2)^2=16a^4-b^4(5x+7y-3)(5x-7y+3)=(5x+(7y-3))(5x-(7y-3))=(5x)^2-(7y-3)^2