25 is 40% of what number

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?

Can someone me and do the problem plz so i can understand it more better

(60 points) explain this in detail