A singer has 20 pairs of earrings , plus another 5 individual earrings which do not match. One morning she reaches into her drawer without looking and pulls out a random earring. What is the probability that the earring she pulls out is part of a pair earrings?

(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

the answer on ed. is:

c. "the graph of f(x) has exactly two x-intercepts."

hope i could someone! : )