Question

Help to find right answer,...

Answer 1

Let g(x) be the inverse of f(x)

Let f(x) = y = 2x + 7
So, y - 7 = 2x
So, x = (y - 7)/2

Replace x→y
And y→x

So, y = (x - 7)/2

This becomes our g(x)
So, g(x) = (x - 7)/2

Now, we want to find g(3).

g(3) = (3-7)/2
So, g(3) = -2

Thus, the answer is -2. (Option B).