Maths problem help Watch

peacheyroses
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So my sixth form set me work to prepare for A level maths and I've gotten to the last 2 questions under the heading 'expanding and simplifying expressions' and im just stuck. It feels so simple but I just can't seem to see the solution!

The first one is 4/(2x + 4) (so 4 over 2x plus 4)

The second one is 2/(5x - 2)

I'd upload an image but the app won't let me :/
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K-Man_PhysCheM
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(Original post by peacheyroses)
So my sixth form set me work to prepare for A level maths and I've gotten to the last 2 questions under the heading 'expanding and simplifying expressions' and im just stuck. It feels so simple but I just can't seem to see the solution!

The first one is 4/2x + 4 (so 4 over 2x plus 4)

The second one is 2/5x - 2

I'd upload an image but the app won't let me :/
It looks like you need to express those as a single algebraic fraction. Do you know how to add numerical fractions? Remember that you must make both denominators the same first by multiplying top and bottom of each fraction by some term, then you can add numerators.

Adding algebraic fractions is just like adding numerical fractions: make both denominators the same by multiplying each fraction by some expression (usually you multiply by the denominator of the other fraction) and then add/subtract numerators as asked.

If you're still struggling, could you please post your working so that we can give more specific help
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K-Man_PhysCheM
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(Original post by peacheyroses)
So my sixth form set me work to prepare for A level maths and I've gotten to the last 2 questions under the heading 'expanding and simplifying expressions' and im just stuck. It feels so simple but I just can't seem to see the solution!

The first one is 4/2x + 4 (so 4 over 2x plus 4)

The second one is 2/5x - 2

I'd upload an image but the app won't let me :/
(Original post by K-Man_PhysCheM)
It looks like you need to express those as a single algebraic fraction. Do you know how to add numerical fractions? Remember that you must make both denominators the same first by multiplying top and bottom of each fraction by some term, then you can add numerators.

Adding algebraic fractions is just like adding numerical fractions: make both denominators the same by multiplying each fraction by some expression (usually you multiply by the denominator of the other fraction) and then add/subtract numerators as asked.

If you're still struggling, could you please post your working so that we can give more specific help
Note that 4\equiv \dfrac{4}{1}, so you are just adding the fractions \dfrac{4}{2x} + \dfrac{4}{1}
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tomahawker314
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for the first one, four can be expressed as 4(2x)/2x. this means that you can add the numerators to get (4+8x)/2x (the 2s can cancel) I'll leave you to get the second
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Quirky Object
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I take it you have to simplify the two expressions?

For the first one, 4 and 2x have a common factor, so you can find the common factor and divide everything by it.

The second one looks pretty irreducible to me :/

Edit: If you meant \frac{4}{2x} + 4 and \frac{2}{5x} - 2, ignore what I just said; please remember to use parentheses in the future to prevent ambiguity (e.g. (4/2x) + 4 = \frac{4}{2x} + 4 and 4/(2x + 4) = \frac{4}{2x + 4})
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peacheyroses
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(Original post by K-Man_PhysCheM)
Note that 4\equiv \dfrac{4}{1}, so you are just adding the fractions \dfrac{4}{2x} + \dfrac{4}{1}
sorry I think you might have read it wrong since I didn't use brackets

the first one is meant to be 4/(2x+4)
and the second is 2/(5x-2)
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MR1999
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(Original post by peacheyroses)
sorry I think you might have read it wrong since I didn't use brackets

the first one is meant to be 4/(2x+4)
and the second is 2/(5x-2)
You just need to take out a common factor from both the numerator and denominator. So the first fraction has a common factor of 2 whilst the second fraction can't be simplified any further.
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K-Man_PhysCheM
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(Original post by peacheyroses)
sorry I think you might have read it wrong since I didn't use brackets

the first one is meant to be 4/(2x+4)
and the second is 2/(5x-2)
Ahh the curse of missing brackets haha xD. Never mind, either way Desmos has given a good response. Just to reiterate, you can divide both the numerator and denominator of the first fraction by 2 to give a simplified fraction (which is another way of saying "taking out a factor of 2" ), while there is no common factor in the second, so no simplification is possible.
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peacheyroses
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(Original post by K-Man_PhysCheM)
Ahh the curse of missing brackets haha xD. Never mind, either way Desmos has given a good response. Just to reiterate, you can divide both the numerator and denominator of the first fraction by 2 to give a simplified fraction (which is another way of saying "taking out a factor of 2", while there is no common factor in the second, so no simplification if possible.
so would I just get 2/(x+2) ?
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K-Man_PhysCheM
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(Original post by peacheyroses)
so would I just get 2/(x+2) ?
Yes
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MR1999
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(Original post by K-Man_PhysCheM)
Ahh the curse of missing brackets haha xD. Never mind, either way Desmos has given a good response. Just to reiterate, you can divide both the numerator and denominator of the first fraction by 2 to give a simplified fraction (which is another way of saying "taking out a factor of 2", while there is no common factor in the second, so no simplification if possible.
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