Question

已知x的平方+3x-6=0,求x的立方+x的平方-12x+10的值.

Answer 1

x^3+x^2-12x+10

=x^3+3x^2-2x^2-6x-6x+10

=x^3+3x^2-6x-2x^2-6x+10

=x(x^2+3x-6)-2x^2-6x+10

=-2x^2-6x+10

=-2(x^2+3x-6)-12+10

=-12+10

=-2