Idon't know what is the factor of 13

Guys i really need or i have to stay late up night

What is the rate of change of a line that passes through (2,-5) and (6,-2)?

The chs baseball team was on the field and the batter popped the ball up. the equation b(t)=80t-16•16+3.5 represents the height of the ball above the ground in feet as a function of time in seconds. how long will the catcher have to get in position to catch the ball before it hits the ground? round to the nearest second