In the table below are values of $f$, $f^\prime$, $g$, and $g^\prime$ for certain arguments $x$. What is the value of $\qquad\displaystyle \dfrac{d}{dx}\big (f(x)\,g(x)\big )$ at $x=1$? $x$ | $f(x)$ | $f^\prime (x)$ | $g(x)$ | $g^\prime (x)$ :-: | :-: | :-: | :-: | :-: | :-: $-1$ | $-3$ | $5$ | $-2.8$ | $2.5$ $0$ | $0$ | $2$ | $0$ | $3$ $1$ | $3$ | $5$ | $2.8$ | $2.5$ [[☃ radio 1]]