nchang

what

No problem! :)

You can factor that equation to this: 49t^2+35-24=0

Now, factor this, and one of its roots will be positive. That positive root is the answer. 

(or, if you can't factor this, Use the quadtradtic formula!)

This might help: 

https://web2.0calc.com/questions/help-in-quadratic-graphing

:)

ok...

Cal just showed my the answer, lol

\(N(N-1)\) 

one must be divisible by 625 and the other must be divisible by 16. This might lead us anywhere?

Yeah, you and I had the same idea! :)

I think we need to use modular arithmetic. This is how far I got \(n^2 - n = n(n - 1)\equiv 0\mod{10000}\).

I just realized that my "n" needs to be capitalized but whatever... :)

n-k+1? I just guessed. I used the pascals triangle, not sure if this is right....