What is the area, in square feet, of the sail?

Which values for a and b will create infinitely many solutions for this system of equations? ax-y=8 2x+y=b

Aretha wanted to gather data about the cost of local bowling leagues in her area. she plotted the data and determined that the average bowling league costs consist of a one-time registration fee and a monthly fee modeled by the equation y = 15x + 20. identify and interpret the y-intercept in this model. the y-intercept is 20. this is the cost per month. the y-intercept is 20. this is the cost of registration. the y-intercept is 15. this is the cost of registration. the y-intercept is 15. this is the cost per month.

What is the point slope form of a line with slope -5 that contains point (2,-1)