Question

x^2+2(a+b)x-3a^2+10ab-3b^2因式分解 快

Answer 1

原式=(x+(a+b))^2-(a+b)^2-3a^2+10ab-3b^2

=(x+(a+b))^2-(4a^2-8ab+4b^2)=(x+(a+b))^2-4(a^2-2ab+b^2)

=(x+(a+b))^2-(2(a-b))^2

=(x+(a+b)-2(a-b))*(x+(a+b)+2(a-b))

=(x+3b-a)*(x+3a-b)