There are currently 20 members in a school Ski club and the dues are $8 per member. To encourage the recruiting of new members, the club treasurer suggests that for each new member recruited, the dues foe all members be reduced by 10 cents. How many new members will result in the maximum membership money? How much will that be?

How many new members will result in the maximum membership money?

n=30

Explanation:

the expression for membership money is ___ (members) * (dues) = money

where n is the number of new members ___ (20 + n) (8 -.1n) = m ___ 160 + 6n -.1n^2 = m

a) substitute the values for new members and solve for m

b) the maximum lies on the axis of symmetry of the quadratic

___ the general formula of the axis of symmetry for ax^2+bx+c is ___ x = - b / (2a)

in this case ___ n = - 6 / [2 (-.1) ] ___ this is the number of new members for maximum money

n=30