X^4-10X^2+9怎么做啊
问题描述:
X^4-10X^2+9怎么做啊
(1)X^4-10X^2+9
(2)(X^2-2X-3)(X^2+2X-24)+90
备注:X^2为X的平方
答
1.X^4-10X^2+9=(x^2 -9)(x^2 -1) =(x-3)(x+3)(x-1)(x+1)2.(X^2-2X-3)(X^2+2X-24)+90 令X^2-2X=a则 原式=(a-3)(a-24)+90=a^2 -27a+162=(a-9)(a-18)=(x^2 -2x-9)(x^2 -2x-18)