Question

Suppose that `x>0` we have `f(2x)= 5/(2+x)`. What is `2f(x)`?

Answer 1

`:.2f(x) =20/(4+x)`

Explanation:

`f(2x) = 5/(2+x) :. f(x) = f( 2*(x/2)) = 5/(2+x/2)=10/(4+x)`

`:.2f(x) =2*10/(4+x) = 20/(4+x)` [Ans]