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# Quick Q watch

1. Just a bit stuck on this q;

Am I right in thinking you first make them all the same number (2) so the top left one becomes 2^3x etc. Then cross multiply to get;

then re-arrange to

I've been hinted that it should be then factorised into brackets, must the closest I can think of is

which obviously works for most of it but ends up with x^2 instead of 15x^2. Can I just stick a 15 in front? or what!

+Rep to help
2. Your first step is correct, making all the bases 2.

You have gone badly wrong after that, did you forget all the rules of indices?

You should obtain a linear equation not a quadratic.
3. (Original post by Mr M)
Your first step is correct, making all the bases 2.

You have gone badly wrong after that, did you forget all the rules of indices?

You should obtain a linear equation not a quadratic.

=

therefore

=

?

I'm confused because our teacher did a similar question to this in a similar way
4. (Original post by jbeach09)
Just a bit stuck on this q;

Am I right in thinking you first make them all the same number (2) so the top left one becomes 2^3x etc. Then cross multiply to get;

then re-arrange to

I've been hinted that it should be then factorised into brackets, must the closest I can think of is

which obviously works for most of it but ends up with x^2 instead of 15x^2. Can I just stick a 15 in front? or what!

+Rep to help
When you cross multiply and all the base of powers is 2 then
you should add the exponents not multiply.
5. (Original post by ztibor)
When you cross multiply and all the base of powers is 2 then
you should add the exponents not multiply.

6. You multiplied again!

In LaTeX you can get a by writing \times
7. (Original post by Mr M)
You multiplied again!

In LaTeX you can get a by writing \times

so

?
8. (Original post by jbeach09)

so

?
Yes but you didn't really need to check with me did you? You could have substituted your answer back into the original question to see if it worked.

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Updated: October 2, 2010
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