Question

If x = 9 – 4√5, find the value of x - 1÷x​

Answer 1

Answer:

please refer to the picture

Answer 2

Answer:

X=9–4√5

Therefore 1/X=1/9–4√5

Rationalising

9+4√5/9²-(4√5)²

9+4√5 / 81–80

9+4√5

X–1/X= 9–4√5–(9+4√5)

=9–4√5–9–4√5

= –8√5