Answer:
slope is -1/3
Explanation:
slope is read rise over run so the line, in this case, fell down 1 and ran 3. Falling means negative so the slope is negative 1 over 3. To easily determine a negative slope, see if the line is moving from top left to bottom right. If so, then it's negative. The other way around is a positive slope.
(i don't do formulas well so I use the graph)