Mathematics, 20.03.2020 08:52, myjavier

Give a combinatorial proof that if n is a positive integer then ∑n k =0 k2 (n k ) = n(n + 1)2n−2.[Hint: Show that both sides count the ways to select a subset of a set of n elements together with two not necessarily distinct elements from this subset. Furthermore, express the righthand side as n(n − 1)2n−2 + n2n−1.]

Answers: 1

Show answers

Other questions on the subject: Mathematics

Mathematics, 22.06.2019 00:00, samafeggins2

Lana's family entered a 5-kilometer race lana's average step length is about 0.5 meter how many steps will she need to take the finish

Answers: 1

continue

Mathematics, 22.06.2019 00:40, ggg509

Atest consists of 10 multiple choice questions, each with 5 possible answers, one of which is correct. to pass the test a student must get 60% or better on the test. if a student randomly guesses, what is the probability that the student will pass the test?

Answers: 2

continue

Mathematics, 22.06.2019 01:30, xojade

The population of a bacteria colony grows by a consistent percentage each hour and can be modeled by the function y = 500(1.16)t. what does the value 500 represent in the function?

Answers: 2

continue

Mathematics, 22.06.2019 02:50, MJyoungboy

Which graph shows the solution set of x^2+4-12x/> 0

Answers: 2

continue

Do you know the correct answer?

Give a combinatorial proof that if n is a positive integer then ∑n k =0 k2 (n k ) = n(n + 1)2n−2.[Hi...