If x-1x=3 then x+1x=?
A
33
B
7
C
23
D
7
Correct Answer: 7
Here, x - 1/x = 3 1/2 we Know, (x - 1/x)2 = (x + 1/x)2 - 4. x. 1/x so, (31/2)2 = (x + 1/x)2 - 4 so, (x + 1/x)2 = 7