若方程x2-3x-1=0的两根为x1、x2,则x1+x2=_,1/x1+1/x2=_.

问题描述:

若方程x2-3x-1=0的两根为x1、x2,则x1+x2=______,

1
x1
+
1
x2
=______.

x1+x2=-

b
a
=-
-3
1
=3,
∵x1+x2=3,x1x2=
c
a
=
-1
1

1
x1
+
1
x2
=
x1+x2
x1x2
=
3
-1
=-3.
故答案为:3,-3.