Given that $f(x)=2 x+3$ and $g(x)=x^{2}-3 x-4$, find $(g \circ f)(7)$ $(g \circ f)(7)=$ (Simplify your answer.)

Step 1 ：Given that \(f(x)=2 x+3\) and \(g(x)=x^{2}-3 x-4\), we need to find \((g \circ f)(7)\).

Step 2 ：First, we find the value of \(f(7)\). Substituting \(x = 7\) into \(f(x)\), we get \(f(7) = 17\).

Step 3 ：Next, we substitute this value into \(g(x)\) to find \(g(f(7))\). Substituting \(x = 17\) into \(g(x)\), we get \(g(f(7)) = 234\).

Step 4 ：Therefore, the value of \((g \circ f)(7)\) is \(\boxed{234}\).