Question

Find k if f of f(k)=5 where f(k)=k-2

Answer 1

Answer: k=7

Step-by-step explanation:

$f(f(k))=5\\f(k)=k-2$

In the second equation, we can see the value of f(k) and we can put it into the first equation like :

$f(f(k)) = 5\\f(k-2)=5\\f(k) -f(2) =5$

We know that f(k) = k - 2 ; Similarly, f(2) = 2 - 2 = 0

$f(k)-f(2)=5\\k-2 -0=5\\k=7$