多项式mx^4+(m-2)x^3+(2n+m/2)x^2-3x+n中不含x^3和x^2项
则 m-2=0 2n+m/2=0
m=2 2n+2/2=0 n=-1/2
原式=2x^4-3x-1/2
x=-1时
原式=2*(-1)^2-3*(-1)-1/2
=2+3-1/2
=5-1/2
=9/2
多项式mx^4+(m-2)x^3+(2n+m/2)x^2-3x+n中不含x^3和x^2项
则 m-2=0 2n+m/2=0
m=2 2n+2/2=0 n=-1/2
原式=2x^4-3x-1/2
x=-1时
原式=2*(-1)^2-3*(-1)-1/2
=2+3-1/2
=5-1/2