Answer
Xmin = -100
Xmax = 60
Ymin = -90
Ymax = 90
Work Step by Step
We need to choose an Xmin, Xmax, Ymin, and Ymax that will contain all the pairs: (-90, 0), (55, 80), (0, -80)
Our Xmin must be lower than the lowest X value, -90. So we can choose -100
Our Xmax must be higher than the highest X value, 55. So we can choose 60
Our Ymin must be lower than the lowest Y value, -80. So we can choose -90
Our Ymax must be higher than the highest Y value, 80. So we can choose 90
