Expand the factorials and you'll see that most of the terms cancel.Hi, could someone please explain how this: [MATH]n!/2!(n-2)![/MATH] gets to this: [MATH]n(n-1)/2[/MATH], thanks
Hi, could someone please explain how this: [MATH]n!/2!(n-2)![/MATH] gets to this: [MATH]n(n-1)/2[/MATH], thanks
Hi, could someone please explain how this: thanks
Hi, could someone please explain how this: [MATH]n!/2!(n-2)![/MATH] gets to this: [MATH]n(n-1)/2[/MATH], thanks
I think the best way to learn about these is to do some: consider 5!7!=5⋅4⋅3⋅2⋅17⋅6⋅5⋅4⋅3⋅2⋅1=7⋅6 Do you see that?Hi, could someone please explain how this: [MATH]n!/2!(n-2)![/MATH] gets to this: [MATH]n(n-1)/2[/MATH]