# Simplifying an equation question

• May 19th 2011, 04:50 AM
PhilC
Simplifying an equation question

I'm really struggling with this one. I know the answer (it's in the back of the book) but I can't see how they get to the answer at all.

<sorry, the display is wrong, the '2' '3' and '4''s are supposed to be powers>

Simplify:

a2b * ac2 / b2c
2c 2b 2a

This obviously equals:

a2b * ac2 *2a
2c 2b b2c

The answer in the book is:

b3
ac

and I don't get how the 'a' got to the bottom of this.

My answer always ends up something like:

a4
b2
• May 19th 2011, 05:27 AM
Soroban
Hello, PhilC!

Quote:

$\text{Simplify: }\:\frac{a^2b}{2c}\cdot \frac{ac^2}{2b} \div \frac{b^2c}{2a}$

$\text{This obviously equals: }\:\frac{a^2b}{2c}\cdot\frac{ac^2}{2b}\cdot\frac{2 a}{b^2c}$ . Right!

$\text{The answer in the book is: }\:\frac{b^3}{ac}$ . ??

$\text{and I don't get how the }a\text{ got to the bottom.}$ . Neither do I

$\text{My answer always ends up: }\:\frac{a^4}{b^2}$ . not quite

$\frac{a^2\rlap{/}b}{\rlap{/}2\rlap{/}c} \cdot\frac{a\rlap{/\!/}c^2}{2\rlap{/}b} \cdot \frac{\rlap{/}2a}{b^2\rlap{/}c} \;=\;\frac{a^4}{2b^2}$

• May 19th 2011, 06:06 AM
PhilC
Thanks, I did say "always ends up something like" and your answer is one of the ways it usually ends up.

I thought I was going mad. I've double checked that I'm looking at the correct question / answer etc many times (if i have double checked many times at least I know it has to be an even number of times).

Finally I can move onto the next section of the book.

Thanks again!