化简求值:x²(x²-x-1)-x(x²-3x),其中x=-2

问题描述:

化简求值:x²(x²-x-1)-x(x²-3x),其中x=-2

x²(x²-x-1)-x(x²-3x),
=x^4-x^3-x^2-x^3+3x^2
=x^4-2x^3+2x^2
=(-2)^4-2×(-2)^3+2×(-2)^2
=16+16+8
=40