Determine the interval(s) at which f(x) is concave down given that f′′(x)=−2x2+6x+8.

Line cd passes through points c(1, 3) and d(4, –3). if the equation of the line is written in slope-intercept form, y = mx + b, what is the value of b? –5 –2 1 5

Ahome improvement store rents it’s delivery truck for $19 for the first 75 minutes and $4.75 for each additional 1/4 hour. if a customer rented the truck at 11: 10 am and returned the truck at 1: 40 pm the same day, what would his rental cost be?

Bernice paid $162 in interest on a loan of $1800 borrowed at 6%. how long did it take her to pay the loan off?