Question

因式分解x^2y^2z^2+x^2z+y^2z+1

Answer 1

法1：

(x^2)(y^2)(z^2)+(x^2)z+(y^2)z+1

=[(x^2)z] *[ (y^2)z]+(x^2)z+(y^2)z+1

=[(x^2)z+1][(y^2)z+1]

法2：

(x^2)(y^2)(z^2)+(x^2)z+(y^2)z+1

=(x^2*y^2)z^2+(x^2+y^2)z+1

=(x^2z+1)(y^2+1) (十字相乘法）