Question 17
The formula which expresses the relationship between $x$ and $y$ as shown in the accompanying table is:
$$
\begin{array}{|c|c|c|c|c|c|} \hline x&0&1&2&3&4\\ \hline y&100&90&70&40&0\\ \hline \end{array}
$$
$$
\begin{array}{|c|c|c|c|c|c|} \hline x&0&1&2&3&4\\ \hline y&100&90&70&40&0\\ \hline \end{array}
$$