What is the slope of the line passing through the points ( 1, 5/7) and (2,2/7)

Its worth 10000000 points need asap if you answer correctly ill mark brainliest

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.

Given sin28.4=.4756, cos28.4=.8796, and tan28.4=.5407 find the cos of 61.6