Hey folks, I'm having a problem with a combination question, hoping to get some ideas of where I'm going wrong from some pros!

Sorry for the bad format, I usually use a program called MathType5 to type out my work, but I can't seem to get the code to translate over here, so I'm gonna do my best with microsoft word and show my work.

Update, so sorry, I just can't get the fractions to translate over.

Solve for "n" in n-1C11 = nC12

I started by using the "n! / (n-r)!r!" formula on both sides, and tried to simplify from there by gathering like terms and then cross multiplying and dividing to get

n!(n-2)!11! = (n-1)!((n-12)!12!)

and then simplifying this into

(n^2-12n)!11n! = (n^2-13n!)(12n-12)!

And it is here that I am stuck, I don't know how to isolate n with factorials being attached to everything.

Again sorry for the bad formatting, any help is appreciated and thanks for taking the time to look at my problem!