Hello there. To solve this question, we'll have to remember some properties about finding slopes of lines and dilations.
Given that the rectangle KLMN is dilated by a scale factor of 3 with the origin being the center of the dilation, resulting in the image K'L'M'N', we need to find the slope of K'L' knowing the slope of KL is -3.
We start by drawing the situation:
Just as an example. The rectangle many not pass through the same points, but the center is at the origin, which means it intersects the x and y axis at symmetric points.
Now, remember a dilation is a transformation that stretches every side at once, or in other words, re-scales the entire figure by a factor.
Since this factor is 3, we would have something like the following: