已知:方程(2007x)²-2006×2008x-1=0的较大实数跟为m,方程x²+2006x-2007=0的较小实数跟为n,则m-n等于:
A.2008 B.2007
C.2008/2007 D.2007/2008
人气:407 ℃ 时间:2020-02-28 06:14:03
解答
解方程:(2007x)²-2006×2008x-1=0,(2007²x+1)(x-1)=0,x1=-1/2007²,x2=1,较大的实数根为m=1
解方程x²+2006x-2007=0,(x-1)(x+2007)=0,x3=1,x4=-2007,较小实数跟为n=-2007,
m-n=1+2007=2008
选A
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