x^2+3x-(a^2+a-2),求因式分解,

x^2+3x-(a^2+a-2),求因式分解,
x^2+3x-(a^2+a-2),求因式分解,

x^2+3x-(a^2+a-2),求因式分解,
x^2+3x-(a^2+a-2)
=x^2+3x-(a+2)(a-1)
=[x+(a+2)][x-(a-1)]

(a^2+a-2) = (a-1)(a+2)
x^2+3x-c = (x+M)(x+N),M*N = -c = -(a-1)(a+2)
然后自己配下数就出来了
结果[x - (a-1)]*[x+(a+2)]

x^2+3x-(a+2)(a-1)=[x-(a-1)][x+(a+2)]=(x-a+1)(x+a+2)