Question

The membership dues at an exclusive club are $1,750 annually. After every year of membership, the dues are lowered by $75. Choose the equation below that gives the dues of members, Dn, in their 7th year of membership.

A.
Dn = $1,750 - $75·n ; D7 = $1,300

B.
Dn = $1,750 - $75·(n - 1) ; D7 = $1,225

C.
Dn = $1,750 - $75·(n - 1) ; D7 = $1,300

D.
Dn = $1,750 - $75·n ; D7 = $1,225

Answer 1

C.

Dn = $1,750 - $75·(n - 1) ; D7 = $1,300

Explanation:

"n" represents each year of membership. The first year that you are a member (n = 1), the fee is $1,750.

In year 2, (n = 2), the fee is $1,750 - $75, which is 75·1. If n=1, and 75 is multiplied by 1, then the formula will use (n - 1).

At this point, the answer will be either B. or C.

Substitute n = 7 into the formula to find the cost in the 7th year.

Dn = $1,750 - $75·(n - 1)

D7 = $1,750 - $75·(7 - 1) Solve inside the brackets first.

D7 = $1,750 - $75·6 Multiply first, then subtract the product from 1750.

D7 = $1,300 Answer

Therefore the answer is C.