X=3 and y=15 twice the sum of a number x and 8

Which undefined geometric term is described as a location on a coordinate plane that is designed by an ordered pair (x,y) ?

Which expression is equivalent to the expression shown?

Lindsay used two points, (x,y; ) and (+2.82), to find the equation of the line, y = mx + b, that passes through the points. y2-y, first, she used the definition of slope and determined that the value of mis x, - . given this information, which expression must represent the value of b?