Question

if x+1/x=7 find x-1/x​

Answer 1

Solution:

It is given that x+1/x = 7 ---(1)

(x-1/x)² = (x+1/x)²-2

= 7²-2

= 49-2

= 47

Therefore,

x - 1/x = ±√47

••••

Answer 2

if

x+1/x=7

then squaring both sides

(x+1/x)^2 =7^2

x^2+1/x^2+2x*1/x

x^2+1/x^2+2=49

x^2+1/x^2=49-2

x^+1/x^2=47

if we have to find the value of x-1/x then

(x-1/x)^2=x^2+1/x^2-(2x*1/x)

(x-1/x)^2 =x^2+1/x^2-2

(x-1/x)^2=47-2

(x-1/x)^2=45

x-1/x=√45

x-1/x=3√5