Answer
$x = -3$ or (B)
Work Step by Step
Find the inverse of $f^{-1}(x)$, or $f(x)$. Switch the "x" and "y" in the equation
$x = 2y + 3, 2y = x-3, y = \frac{x-3}{2}$. Now, equate the function and the inverse and solve for x
$f(x) = f^{-1}(x), 2x+3 = \frac{x-3}{2}$
Rearranging, starting by multiplying by 2: $4x+6=x-3, 3x = -9, x = -3$
The answer is $x = -3$ or (B)
