Graph (3,2) (-6,2) (-6,-8) (3,-8) on the coordinate plane

A negative power means the quantity is in the denominator of a fraction.

(2) to the -1 power means 1/2

6 to the -3 power means 1/(6 to the 3 power).

13xy to the -8 power means 1 / (13xy to the 8 power)

That's something like  1 / [ (13 to the 8 power) (x to the 8 power) (y to the 8 power) ]