Fitness First is running a promotion right now which includes a discounted annual membership fee of $50 plus a $5 charge every time you use the gym facilities. If a person plans to use the gym at least 3 times a week for the entire year, how much will it cost them?

(n^3 - n)

= n(n-1)(n+1)

since it is divisible by 3 and 2 ,because it is a multiple 3 consecutive number

if, n-1 is odd then n+1 is also odd, then it is a multiple of 9

but if, n-1 is even then n+1 is also even, then it is a multiple of 4

so, largest multiple = max(9*2, 4*3) = max(18, 12) = 18

stop cheating

step-by-step explanation: