Systems of equations: solve this & show your work! you : )

Aline passes through 3,7 and 6,9 what equation represents the line

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.

What is the 9th term in the geometric sequence described by this explicit formula? an=-6. (2)(n-1) apex