We determine the zeros of the function $y(x)=5x+3$.
$$\begin{align}
5x+3=0 \Leftrightarrow 5x=-3\\
\Leftrightarrow x=-\frac{3}{5}.
\end{align}$$
Hence, the only zero of the function $y(x)$ is $x=-\frac{3}{5}$.
$$\begin{align}
5x+3=0 \Leftrightarrow 5x=-3\\
\Leftrightarrow x=-\frac{3}{5}.
\end{align}$$
Hence, the only zero of the function $y(x)$ is $x=-\frac{3}{5}$.