Question

If a=9-4√5,find value of a-1/a

please help me ​

Answer 1

Answer:

a=9-4 root 5

1/a=1/(9-4 root 5

=1*(9+4 root5)/(9) 2-(4 root 5)2

=(9+4 root5) /81-80

=9+4root 5

a-1/a=9-4root5-(9+4root 5)

=9-4 root 5- 9-4 root 5

= 8 root 5

Step-by-step explanation:

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