Question

如果关于x的多项式(3x^2+2mx-x+1)+(2x^2-mx+5)-(5x^2-4mx-6x)的值与x无关,求m值.

Answer 1

(3x^2+2mx-x+1)+(2x^2-mx+5)-(5x^2-4mx-6x)

=(5m+5)x+6

值与x无关

5m+5=0

m=-1

m^2+(4m-5)+m=1-4-5-1=-9