How much is 35 ounces of apple sause if 40 ounces cost $2.80

For the equations below which statement is true ?

If the scale factor between two circles is 2x/5y what is the ratio of their areas?

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.