Can some explain to me what coefficient means?

What is the equation of the line shown in this graph?

The clayton family’s pool has vertices at the coordinates (0, 2), (0, 5), (2, 5), (2, 6), (5, 6), (5, 1), (2, 1), and (2, 2). if each grid square has an area of 9 square feet, what is the area of the pool?

What fraction is equivalent to 0.46464646··· a. 46⁄999 b. 46⁄100 c. 46⁄99 d. 23⁄50