Question

（-x)的3次方乘以x的2n减1次方加x的2n次方乘以（-x）的2次方

Answer 1

(-x)^3*x^(2n-1)+x^2n*(-x)^2

=-x^3*x^(2n-1)+x^2n*x^2

=-x^(3+2n-1)+x^(2n+2)

=-x^(2n+2)+x^(2n+2)

=0