What is 15-2x> 9 can you plz me'

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?

In which direction does the left side of the graph of this function point? a(x) = 3x - x2 + 4x - 2

How is this equation completed? i cannot find any examples in the book.