f(x)=40+4x+x^2 (e) What is the slope of the chord connecting the points (5, f (5)) and (5 + ∆x, f (5 + ∆x)), when ∆x = 5? Really confused on how to do this and what it means

Can somebody 1. what is the formula for finding the vertical distance between two points on a coordinate plane?

Stefanie is painting her bedroom. she can paint 2 1/3 square feet in 4/5 of an hour. how many square feet can she paint in one hour?

Charlie is at an amusement park that has 18 different rides. each ride costs $1.75. the function c(r) = 1.75r represents the total amount of money that charlie will spend if he goes on r rides, but he never goes on the same one more than once. what domain and range are reasonable for the function?