There are $15$ skaters in the Olympic women's competition, including $4$ Americans. The gold medal goes to first place, silver to second, and bronze to third. In how many ways can the medals be awarded to three of the $15$ skaters, if exactly one of the Americans wins a medal?

hello from mrbilldoesmath!

answer:

a(n) - a(n-1) -3

discussion:

this ones a bit interesting. given a(n) = 5 - 3n consider this:

a(n-1) = 5 - 3(n-1)

          = (5 - 3n) + 3             => but a(n) = 5 - 3n, the first term

          = a(n)   + 3                 => subtract 3 from both sides

a(n-1) -3 = a(n)  

or

a(n) - a(n-1) -3

you,

mrb

constants mean the stopped points or the points on a graph that nothing is changing, hope this

step-by-step explanation:

nada

step-by-step explanation:

your answer would be 12