Understanding Exponent Multiplication: cnxn-1

AI Thread Summary
The discussion focuses on simplifying the expression x(cnxn-1) to cnxn. The key point is that when multiplying x, which is x^1, by cnxn-1 (or x^(n-1)), the exponents add according to the law of exponents: (a^m)(a^n) = a^(m+n). This means that x^1 multiplied by x^(n-1) results in x^(1 + (n-1)), which simplifies to x^n. The confusion arises from misunderstanding how the exponents interact, but the correct application of exponent rules clarifies the solution. Understanding these basic laws of exponents is essential for simplifying expressions correctly.
PhysicsBoyMan
Messages
33
Reaction score
0

Homework Statement


x(cnxn-1)

3. The Attempt at a Solution

I know that the answer is cnxn

I'm not sure why though. My thinking is that we have cnxn-1 and we multiply that by x. x times x is x2 so I'm expecting a 2 to interact with the n-1 in the exponents. I'm just not sure how n-1 interacts with 2 to produce n.

I don't add n-1 + 2 to get n + 1 because I already have the answer and its not that. I just can't see how I would get from n-1 to n by interacting with a 2.

Thanks for the help.
 
Physics news on Phys.org
PhysicsBoyMan said:

Homework Statement


x(cnxn-1)

3. The Attempt at a Solution

I know that the answer is cnxn

I'm not sure why though. My thinking is that we have cnxn-1 and we multiply that by x. x times x is x2 so I'm expecting a 2 to interact with the n-1 in the exponents. I'm just not sure how n-1 interacts with 2 to produce n.

I don't add n-1 + 2 to get n + 1 because I already have the answer and its not that. I just can't see how I would get from n-1 to n by interacting with a 2.

Thanks for the help.
You may know the answer to the question.

We're not any good at guessing just what that question might be.

What is the question?
 
The question is the multiplication of x times cnxn-1
 
PhysicsBoyMan said:

Homework Statement


x(cnxn-1)

3. The Attempt at a Solution

I know that the answer is cnxn

I'm not sure why though. My thinking is that we have cnxn-1 and we multiply that by x. x times x is x2 so I'm expecting a 2 to interact with the n-1 in the exponents. I'm just not sure how n-1 interacts with 2 to produce n.

I don't know where you are getting that you are multiplying x times x here.

You are multiplying x times xn-1, which is something different.

That's what x(cnxn-1) means. It can also be written as c ⋅ n ⋅ x ⋅ xn-1
 
PhysicsBoyMan said:
The question is the multiplication of x times cnxn-1
Oh! You want to simplify the product, x⋅cnxn-1 .

So the 'question' is:
What is the result of simplifying x⋅cnxn-1 ?
And you want to know how it is that simplifies to be cnxn .
.
 
Have you never actually taken an Algebra class? If you have you should have learned one of the basic 'laws of exponents':
(a^m)(a^n)= a^{m+n}. Here the problem is to multiply x, which is the same as x^1, by x^{n-1}.
Mod note: Portion deleted as too much help.
 
Last edited by a moderator:
Back
Top