Determined an equation for the pictured graph

15 points! write the slope-intercept form of the equation of the line through the given point with the given slope. use y-y = m(x-x) to solve. through (2,5) slope= undefined

Acyclist bike x distance at 10 miles per hour .and returns over the same path at 8 miles per hour.what is the cyclist average rate for the round trip in miles per hour ?

Im so bad at fractions they are not my best math thing to work on