PLS HELP I need this pls someone

Aparallelogram has two side lengths of 5 units. three of its sides have equations y = 0, y = 2, y = 2x. find the equation of the fourth side.

Agreeting card company can produce a box of cards for $7.50. if the initial investment by the company was $50,000, how many boxes of cards must be produced before the average cost per box falls to $10.50?

What are the coordinates of the midpoint of ab? ,1/2) /2,-1) ,-3/2) /2,-2)