Question

试说明：不论x、y取何值,整数（3^3+5*x^2+4*x-1)-(-x^2-3x+2x^3-3)+(8-7x-6x^2

Answer 1

（x^3+5*x^2+4*x-1)-(-x^2-3x+2x^3-3)+(8-7x-6x^2+x^3）

=3x^3+5*x^2+4*x-1+x^2+3x-2x^3+3+8-7x-6x^2+x^3

合并同类项

=10

所以值恒不变.