因式分解法计算:(1) -7ab-14abx+49aby; (2) (x-1)^3y^3+(1-x)^3z^3;(3)(x^2+x)^2 -3(x^2+x)+2; (4) x^2-y^2-z^2+2yz;(5)3x^2+2xy-8y^2; (6) x^2-x-30; (7) x^4+4.
问题描述:
因式分解法计算:
(1) -7ab-14abx+49aby; (2) (x-1)^3y^3+(1-x)^3z^3;
(3)(x^2+x)^2 -3(x^2+x)+2; (4) x^2-y^2-z^2+2yz;
(5)3x^2+2xy-8y^2; (6) x^2-x-30; (7) x^4+4.
答
(1) -7ab-14abx+49aby; = -7ab(1+2x-7y) (2) (x-1)^3y^3+(1-x)^3z^3=(x-1)³(y³-z³)=(x-1)³(y-z)(y²+yz+z²)(3)(x^2+x)^2 -3(x^2+x)+2; =(x²+x-1)(x²+x-2)=...