Whit is the sum of the interior angle measures of a convex pentegon

Answer question above and explain each step : )

At 6 1/2 cents per pound of string beans how much does 7 pounds cost

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.