Question

若多项式2mx^2-x^2+5x+8-(7x^2

Answer 1

若多项式2mx^2-x^2+5x+8-(7x^2-3y+5x)与x无关,求m^2-(2m^2-(5m-4)+m)的值

(2m-8)x^2+8+3y与x无关 => 0x^2+8+3y =>2m-8=0 => m=4

=>m^2-(2m^2-(5m-4)+m)=m^2-2m^2 +5m-4-m=-m^2+4m-4=-(m^2-4m+4)=-(m-2)^2

=-2^2=-4.ans