# Maths help

Help with the following question please
(edited 2 months ago)
Help with the following question please

What have you tried? The symmetry in the problem should give a hint about one common factor.
(edited 2 months ago)
Original post by mqb2766

What have you tried? The symmetry in the problem should give a hint about one common factor.

Can you explain further please I’ve attempted this 5 times
Can you explain further please I’ve attempted this 5 times

If there was no +/-8s in the expression, so
a^4-b^4 / a^3-b^3
could you spot a common factor (factor theorem)? Then how can this be modified when you consider the original expression.
Original post by mqb2766

If there was no +/-8s in the expression, so
a^4-b^4 / a^3-b^3
could you spot a common factor (factor theorem)? Then how can this be modified when you consider the original expression.

I’m still a bit lost, could you tell me the answer and how you got to it? I’ve got to submit it before 1pm. Thanks
I’m still a bit lost, could you tell me the answer and how you got to it? I’ve got to submit it before 1pm. Thanks

For the simplified expression, you should see subbing a=b makes both the numerator and denomiantor zero so that means both have a factor (a-b) which can be cancelled. Then think how that can be modified for the actual question.
Original post by mqb2766

For the simplified expression, you should see subbing a=b makes both the numerator and denomiantor zero so that means both have a factor (a-b) which can be cancelled. Then think how that can be modified for the actual question.

Yeah it should cancel to a-b/1 but I don’t know how to modify it for the actual expression?
Yeah it should cancel to a-b/1 but I don’t know how to modify it for the actual expression?

It does not cancel to that expression as there is only a single common factor.
The question is all about spotting a (common) factor using the factor theorem so its worth having a read through your notes, trying some (other) simplified questions. So what if the exponents smaller ...
Ok I’ll do that, do I need to expand the brackets?
Ok I’ll do that, do I need to expand the brackets?

Take the hint about thinking about a simpler (smaller exponent) problem to try and spot the factor first. Or if you were solving numerator = 0 or denominator = 0, what is the solution, what is the common factor, ...
(edited 2 months ago)
Original post by mqb2766

Take the hint about thinking about a simpler (smaller exponent) problem to try and spot the factor first. Or if you were solving numerator = 0 or denominator = 0, what is the solution, what is the common factor, ...

Can I show you what I’m doing in dms? I’m actually in uni, this is a topic we haven’t been taught, we’re just expected to finish quizzes using a level knowledge, I posted in this subreddit because I’m doing foundation year
Can I show you what I’m doing in dms? I’m actually in uni, this is a topic we haven’t been taught, we’re just expected to finish quizzes using a level knowledge, I posted in this subreddit because I’m doing foundation year

Tbh, Ive given about all the hints I can without simply giving you the common factor, and the previous hint about when is (both) the numerator = 0 and denominator = 0 pretty much gives it away. If you cant solve this, just post your attempt, but its almost gcse knowledge to get that part, then a bit of messy division/factorisation to get the actual A and B required.
Original post by mqb2766

Tbh, Ive given about all the hints I can without simply giving you the common factor, and the previous hint about when is (both) the numerator = 0 and denominator = 0 pretty much gives it away. If you cant solve this, just post your attempt, but its almost gcse knowledge to get that part, then a bit of messy division/factorisation to get the actual A and B required.