O=3, 9, 15, 21, 27, 33, 39 in set builder notation

Where m is the slope of the line and b is the y-intercept of the line, or the y-coordinate of the point at which the line crosses the y-axis. to write an equation in slope-intercept form, given a graph of that equation, pick two points on the line and use them to find the slope. this is the value of m in the equation.

Ithink the answer is $2.10

7for nonmembers i think