Find the value of y when x=3: y= 2x +1

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?

What is the slope of the line that contains the points (-2,1) and (0,-3)

The two square pyramids are similar. find the total volume of both pyramids if the ratio of their surface areas is 9/16