an equation perpendicular to the equation given will have a slope of -1, because a perpendicular slope is opposite and reciprical. if it goes through the point 4,-1 and has a slope of -1, the y intercept has to be 3. y = -x + 3
So if you bring 10 empty bottles you can get 1 drink. So if
you bring 100 bottles you can have 10 drinks. When that 10 drinks will be
empties you can still change it for another 1 drink. So the total drinks you
can have from 100 bottle is 11 drinks
