What is the answer for this?

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 holiday party will cost $160 if 8 people attend.if there are 40 people who attend the party, how much will the holiday party cost

Jalen charges $25.50 for every 3 hours of yard work he does for his neighbors. ralph charges $34 for every 4 hours of work that he does. who charges less? opinions: 1.they charge the same amount 2.jalen 3.ralph