What does an exclamation mark mean in algebra?

Usually when we write N! , we mean the PRODUCT of the integers 1 to N inclusive, not the sum. But let's assume they really meant sum I think the first difficulty here is the way the problem is stated.It's in very formal language, which can be a little confusing at first First let's tackle the question.

They're saying, "Sometimes we want to add up all the integers between one and n, and do math with that sum. Rather than having to write out 1 + 2 + 3 ... etc., over and over, we decided to use an exclamation point. So when we say 4!

, we mean 1 + 2 + 3 + 4, and when we say n! , we mean 1 + 2 + 3 + ... + n Does that make sense? Now, given all that, they give you a problem to solve that has two important steps: 10!

- 9! = k! First step: What's k!?

Second step: What's k? Now that we've talked about the question, let's talk about solving it. It helps to write out the values you're adding and subtracting this way: 10!

- 9! ---- k! 10 + 9 + 8 + 7 + 6 + 5 + 4 + 3 + 2 + 1 - (9 + 8 + 7 + 6 + 5 + 4 + 3 + 2 + 1) In that case, what's k!?

Given that k! Is: 1 + 2 + ... + k can you figure out what k is, given k!? P.S. I got this from Math Forum-Ask Dr. Math.

This is not my own.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.