Question

if x+1/x = 9 , find value of x-1/x = ?
Answer this question to get 15 points.

Answer 1

x+1/x=9

Squaring both sides,

(x+1/x)²=81
x²+2×x×1/x+1/x²=81
x²+1/x²+2=81
x²+1/x²=79------------1)


(x-1/x)²=x²+1/x²-2×x×1/x
=x²+1/x²-2
=79-2-------------from 1)
=77

x-1/x=+/-√77

Answer 2

▌│█║▌║▌║ Hi friend ║▌║▌║█│▌

▌│█║▌║▌║ Your answer ║▌║▌║█

Given that : - x + 1/x = 9

To find : - value of x - 1/x.

n̲̅o̲̅w̲̅,

x + 1/x = 9

=> (x + 1/x)² = (9)² [squaring both sides. ]

=> x² + 1/x² + 2 = 81

=> x² + 1/x² = 81 - 2

=> x² + 1/x² = 79

=> x² + 1/x² - 2 = 79 - 2 [subtracting 2 from both sides]

=>(x - 1/x)² = 77

=> x - 1/x = ±√77

h̲̅o̲̅p̲̅e̲̅ i̲̅t̲̅ h̲̅e̲̅l̲̅p̲̅s̲̅