Question

if x-1/x = sq root 5 find the value of x +1/x​

Answer 1

Answer:

x = (2 + √5)

x + 1/x

= 2 + √5 + 1/(2 + √5)

(2 + √5)² + 1/(2 + √5)

= 4 + 5 + 4√5 + 1 / (2 +√5)

= 10 + 4√5 / ( 2 + √5)

= 10 + 4√5(2 - 4√5) / 2² - √5²

= 20 -40√5 +8√5 - 90 / 4 - 5

= -70 - 32√5 / -1

= 70 + 32√5