若多项式(2mx^2-x^2+3x+1)-(5x^2-4y^2+3x)的值与X无关,求2m^2-〔3m^2+(4m-5)+m〕的值~

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若多项式(2mx^2-x^2+3x+1)-(5x^2-4y^2+3x)的值与X无关,求2m^2-〔3m^2+(4m-5)+m〕的值~
若多项式(2mx^2-x^2+3x+1)-(5x^2-4y^2+3x)的值与X无关,求2m^2-〔3m^2+(4m-5)+m〕的值~

若多项式(2mx^2-x^2+3x+1)-(5x^2-4y^2+3x)的值与X无关,求2m^2-〔3m^2+(4m-5)+m〕的值~
(2mx^2-x^2+3x+1)-(5x^2-4y^2+3x)
=2mx^2-x^2+3x+1-5x^2+4y^2-3x
=2mx^2-6x^2+4y^2+1
由题意可知:
2mx^2-6x^2=0
m=3
2m^2-〔3m^2+(4m-5)+m)
=2m^2-3m^2-4m+5-m
=-m^2-5m+5
代入得:
-3^2-5*3+5
=-9-15+5
=-19

若多项式(2mx^2-x^2+3x+1)-(5x^2-4y^2+3x)的值与X无关
===>2m-5=0===>m=5/2
===>2m^2-(3m^2+(4m-5)+m)=-m^2-5m+5=-25/4-25/2+5=-5/4