a2+3a-1=0 b2+3b-1=0,则b/a+a/b=

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a2+3a-1=0b2+3b-1=0,则b/a+a/b=a2+3a-1=0b2+3b-1=0,则b/a+a/b=a2+3a-1=0b2+3b-1=0,则b/a+a/b=a2+3a-1=0b2+3b-1

a2+3a-1=0 b2+3b-1=0,则b/a+a/b=
a2+3a-1=0 b2+3b-1=0,则b/a+a/b=

a2+3a-1=0 b2+3b-1=0,则b/a+a/b=
a2+3a-1=0 b2+3b-1=0
可以看成 x2+3x-1=0的两根为a,b
x1+x2=a+b=-3
x1*x2=ab= -1
b/a+a/b=(a2+b2)/ab
=[(a+b)2-2ab]/ab
=(9+2)/(-1)
=-11

2或-11.

由题意:a和b是方程x²+3x-1=0的两个根
所以a+b=-3
ab=-1
a^2+b^2=(a+b)^2-2ab=11
b/a+a/b=(a^2+b^2)/ab=-11