How can you tell if a number is devisible by 3?

Find the slope of the line y =8/9x + 1.

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.

F(x) = 1/x g(x)=x-4 can you evaluate (g*f)(0) ? why or why not?