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Erm, can anyone decipher this math question?

See attached:

IMG_0944.jpeg



They’re asking me to simply which is fine but am I meant to be just equating them? The question feels incomplete.
(edited 1 year ago)

Reply 1

Original post by KingRich
See attached:
IMG_0944.jpeg
They’re asking me to simply which is fine but am I meant to be just equating them? The question feels incomplete.

Theyre the same expression. So I guess theyre just giving you the first step on the right. So start with the left and keep going ...

Reply 2

Original post by mqb2766
Theyre the same expression. So I guess theyre just giving you the first step on the right. So start with the left and keep going ...

That’s what I was confused about. I’ve simplifying both sides which left me baffled lol

Reply 3

Original post by KingRich
Do you think they’re expecting me to cancel out the logs? I end up with x³+y+6 in its most simplified expression.

The steps in the op are not right and youd expect the final expression to contain log(x) and log(y). So
log(8x^3) = log((2x)^3)
or
log(8x^3) = log(8 ) + log(x^3)
not what youve written. The cube has to apply to the whole argument to bring it outside the log.
(edited 1 year ago)

Reply 4

Original post by mqb2766
The steps in the op are not right and youd expect the final expression to contain log(x) and log(y). So
log(8x^3) = log((2x)^3)
or
log(8x^3) = log(8 ) + log(x^3)
not what youve written. The cube has to apply to the whole argument to bring it outside the log.

I just deleted my previous message because I realised my thinking is incorrect. Do you think it’s best to just expand the expression?

Such as 3log₂(x)+2 - log₂(y),

Reply 5

Original post by KingRich
I just deleted my previous message because I realised my thinking is incorrect. Do you think it’s best to just expand the expression?
Such as 3log₂(x)+2 - log₂(y),

Its going to be something like that. Also note you can divide 8 by 2 right at the start.

Reply 6

Original post by mqb2766
Its going to be something like that. Also note you can divide 8 by 2 right at the start.

Yeah, I just noticed that at the beginning. Essentially that’s what simplifying would have been lol.

I’m contacting to confirm because that doesn’t require using any log laws lol

Reply 7

Original post by KingRich
Yeah, I just noticed that at the beginning. Essentially that’s what simplifying would have been lol.
I’m contacting to confirm because that doesn’t require using any log laws lol

Its not a big thing. They could argue that without doing the division the question is based on 8=2^3 and log_2(2)=1. If you do the division at the start, you need to recognise 4=2^2 so log_2(4) = ...

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