PLEASE HELP, I don't understand what to do, your help would be highly a welcomed

How can we find the measure of an exterior angle if we know the measurement of an interior angle

Joseph haydn pet store offers wide variety of leashes for dogs. the store purchases one popular type of leash from its manufacturer for $4.38 each. joseph haydn pets marks up leashes at a rate of 238% of cost. what is the retail price of the popular leash?

Find an equation for the linear function which has slope -10 and x-intercept -7