已知实数a,b满足条件a2-7a+2=0,b2-7b+2=0(a≠b),则b/a+a/b=_.

问题描述:

已知实数a,b满足条件a2-7a+2=0,b2-7b+2=0(a≠b),则

b
a
+
a
b
=______.

由实数a,b满足条件a2-7a+2=0,b2-7b+2=0,
∴可把a,b看成是方程x2-7x+2=0的两个根,
∴a+b=7,ab=2,

b
a
+
a
b
=
a2+b2
ab
=
(a+b)2-2ab
ab

=
49-4
2
=
45
2

故答案为:
45
2