Help me with my math test please

Can someone answer this question? : )

Parabolas y=−2x^2 and y=2x^2 +k intersect at points a and b that are in the third and the fourth quadrants respectively. find k if length of the segment ab is 5.

The pair of coordinates that do not represent the point( 5,150’) is a. (5,-210) b. (5,210) c. (-5,330) d. (-5,-30)