So - I know all the steps, I just need help with a gap.

Prove

Ok, proof by Induction:

Since 4! = 24 which is , for n=4.

Let k be a positive integer [math\geq4[/tex] and suppose .

Then,

Here's where I'm stuck. I know but how can I show that ?

From then, I can show

Therefore, , so .

Please help me out with this way of solving the proof, I'm sure there are other ways.

any help: please!!!??