indices

andyboy179 · #1 $Old$ November 7th, 2009, 08:16 AM

hi, this is my question:
? 2????????? 3
2ab divided ab
???????????3?4
would it = 2ab

PLEASE IGNORE THE ?s I NEED THEM THERE SO THE NUMBERS WILL BE ABOVE THE LETTERS. ON THE QUESTION 2 IS ABOVE a AND 3 IS ABOVE b.

HallsofIvy · #2 $Old$ November 7th, 2009, 10:23 AM

Quote:

Originally Posted by andyboy179 $View Post$

hi, this is my question:
? 2????????? 3
2ab divided ab
???????????3?4
would it = 2ab

PLEASE IGNORE THE ?s I NEED THEM THERE SO THE NUMBERS WILL BE ABOVE THE LETTERS. ON THE QUESTION 2 IS ABOVE a AND 3 IS ABOVE b.

That still does not make a whole lot of sense. Powers are most simply represented by "^". That is (2a^2b) divided by (ab^3).

No, that is not 2a^3b^4. Write this as the fraction (2a^2b)/(ab^3) and cancel where you can.

andyboy179 · #3 $Old$ November 7th, 2009, 10:28 AM

Quote:

Originally Posted by HallsofIvy $View Post$

That still does not make a whole lot of sense. Powers are most simply represented by "^". That is (2a^2b) divided by (ab^3).

No, that is not 2a^3b^4. Write this as the fraction (2a^2b)/(ab^3) and cancel where you can.

im confused! so i have this, (2a^2b)/(ab^3) would it = 2a^2b^3?

skeeter · #4 $Old$ November 7th, 2009, 02:31 PM

Quote:

Originally Posted by andyboy179 $View Post$

im confused! so i have this, (2a^2b)/(ab^3) would it = 2a^2b^3?

$\frac{2a^2 b}{ab^3} = \frac{2 \cdot a \cdot a \cdot b}{a \cdot b \cdot b \cdot b} = \frac{2a}{b^2}$

andyboy179 · #5 $Old$ November 8th, 2009, 06:55 AM

Quote:

Originally Posted by skeeter $View Post$

$\frac{2a^2 b}{ab^3} = \frac{2 \cdot a \cdot a \cdot b}{a \cdot b \cdot b \cdot b} = \frac{2a}{b^2}$

how did you get this $\frac{2a}{b^2}$ ?

because there are 2 a's on the top and 1 on the bottom and the line inbetween them means divide and 2 divide 1= 2. but on the top there is 1 b and on the bottom there is 3 b's and 1 divide 3 = 0.3

skeeter · #6 $Old$ November 8th, 2009, 07:41 AM

Quote:

Originally Posted by andyboy179 $View Post$

how did you get this $\frac{2a}{b^2}$ ?

because there are 2 a's on the top and 1 on the bottom and the line inbetween them means divide and 2 divide 1= 2. but on the top there is 1 b and on the bottom there is 3 b's and 1 divide 3 = 0.3

no.

you need a lesson on exponents ...

Exponents: Basic Rules

go through all 5 pages thoroughly.

HallsofIvy · #7 $Old$ November 8th, 2009, 08:01 AM

Or simply that $\frac{2a^2 b}{ab^3} = \frac{2 \cdot a \cdot a \cdot b}{a \cdot b \cdot b \cdot b} = 2\left(\frac{a}{a}\right)\left(a\right)\left(\frac{b}{b}\right)\left(\frac{1}{b^2}\right)$

And $\frac{a}{a}= \frac{b}{b}= 1$ .