Answer:
[tex]\sqrt{153}[/tex]
Step-by-step explanation:
Using Pythagoras in 3D.
[tex]a^2+b^2=c^2[/tex] (The distance between two points in a direction)
For the x-plane.
[tex](-9)^2+(-2)^2=c^2\\85=c^2\\c=\sqrt{85}[/tex]
For the y-plane.
[tex]8^2+2^2=c^2\\68=c^2\\c=\sqrt{68}[/tex]
Finding the shortest distance between those two points.
[tex]\sqrt{68}^2+\sqrt{85}^2=c^2\\68+85=c^2\\153=c^2\\c=\sqrt{153}[/tex]