turkey-yks 2025 Q7
Evaluate Composition from Algebraic Definitions
Let $a$ and $b$ be real numbers. For the functions $f$ and $g$ defined on the set of real numbers as
$$\begin{aligned}
& f(x) = \frac{x}{2} + 1 \\
& g(x) = 2x - 3
\end{aligned}$$
the equalities
$$\begin{aligned}
& (f + g)(a) = f(a) \\
& (f - g)(b) = g(b)
\end{aligned}$$
are satisfied. Accordingly, what is the value of $(f \circ g)(a \cdot b)$?
A) $\frac{1}{2}$ B) $\frac{5}{2}$ C) $\frac{9}{2}$ D) $\frac{13}{2}$ E) $\frac{17}{2}$