Question

if n+2C8:n-2P4=57:16,then prove that n=19​

Answer 1

Answer:

proved

Step-by-step explanation:

n+2C8 = n+2!÷8!(n-6)!

n-2P4 = n-2! ÷ (n-6)!

n+2C8:n-2P4=57:16

n+2!÷8!(n-6)! / n-2! ÷ (n-6)! = n+2!÷8! ( n-2)!

( n+2  )(n+1 )n(n-1) = 57*8!/16 = 57*7!/2 = 19*3*7*6*5*4*3 = 21*20*19*18

n = 19