Question

Urgent math help needed will mark brainliest

Answer 1

Remark

Many calculators have a key that will do this in one step. Mine is one of them. So let's start with the answer and then we'll do it the long way.

9C3 = 84. You put it into your calculator as 9   2nF   nCr 3 =

Solution

$\dfrac{9!}{(n - 3)!3!} = \dfrac{9*8*7*6!}{6!*3!}=\dfrac{9*8*7}{6}$

3*4*7 = 84 which is what you set out to show.