Question

因式分解,一题(x²+3x-2)(x²+3x+4)-16

Answer 1

设y=x^2+3x+1

(x^2+3x-2)(x^2+3x+4)-16

=(y-3)(y+3)-16

=y^2-9-16

=y^2-25

=(y+5)(y-5)

=(x^2+3x+6)(x^2+3x-4)