Answered

Westonci.ca is the ultimate Q&A platform, offering detailed and reliable answers from a knowledgeable community. Get precise and detailed answers to your questions from a knowledgeable community of experts on our Q&A platform. Join our platform to connect with experts ready to provide precise answers to your questions in different areas.

Show that nC6 = nC4, find n​

Sagot :

asuwafohjames

Answer:

n = 10

Step-by-step explanation:

From the question,

nC6 = nC4

n!/6!(n-6)! = n!/4!(n-4)!

Simplifying n! out of the equation

⇒ 1/6!(n-6)!  = 1/4!(n-4)!

Crossmultiplying

4!(n-4)! = 6!(n-6)!

4!(n-4)! = 6×5×4!(n-6)!

(n-4)! = 30(n-6)!

(n-4)(n-5)(n-6)! = 30(n-6)!

⇒ (n-4)(n-5) = 30

n²-4n-5n+20 = 30

n²-9n+20-30

n²-9n-10 = 0

Solving the quadratic equation,

n-10n+n-10 = 0

(n-10n)+(n-10) = 0

n(n-10)+1(n-10) = 0

(n+1)(n-10) = 0

Either

n+1 = 0

n = -1

or

n-10 = 0

n = 10

n canot be a negative value,

Therefore, n = 10

Thank you for your visit. We are dedicated to helping you find the information you need, whenever you need it. We hope our answers were useful. Return anytime for more information and answers to any other questions you have. We're glad you chose Westonci.ca. Revisit us for updated answers from our knowledgeable team.