Answer
$X[-30,50,10]$ by $Y[-90,50,10]$
Work Step by Step
1. Examine the given coordinates, we can find the minimum and maximum of each direction as $X, -20, 40$ and $Y, -80, 40$
2. Set scale=10 and the window 10 unit larger each direction to cover the above numbers, we can get the viewing window as $X[-30,50,10]$ by $Y[-90,50,10]$ where the first number in the bracket represents the minimum value, the second number the maximum value, and the last number the scale.
