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to ask you to simplify this (GCSE maths mock)

42 replies

nojellybabies · 10/01/2019 16:15

x-to-the-5 MINUS 4*x-cubed
OVER
3x-6

I've got A level maths and I'm stuck...

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imip · 10/01/2019 16:32

I’m going to fail 😢

nojellybabies · 10/01/2019 16:33

thank you. Green Eggs.

how did you get that?

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GreenEggsHamandChips · 10/01/2019 16:33

For the second question

to ask you to simplify this  (GCSE maths mock)
nojellybabies · 10/01/2019 16:34

you've got four months to go imip.
you can do it.

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nojellybabies · 10/01/2019 16:37

is

1/xsquared

the same as
x -to-the-power-of-minus-2?

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GreenEggsHamandChips · 10/01/2019 16:38

Yeah

PurpleDaisies · 10/01/2019 16:38

Solution to the second question

to ask you to simplify this  (GCSE maths mock)
PurpleDaisies · 10/01/2019 16:39

Oops. Missed p2.

nojellybabies · 10/01/2019 16:44

so when the superscripted "to the power of" number/symbol moves above or below the line, its sign switches from positive to negative or vice versa?

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PurpleDaisies · 10/01/2019 16:45

That’s right. So 1 over x5 = x-5

Passthepigs · 10/01/2019 16:46

Think others have beat me to it, had to sort toddlers dinner!

to ask you to simplify this  (GCSE maths mock)
PurpleDaisies · 10/01/2019 16:46

Roots become fractional indices eg square root x = x^1/2

nojellybabies · 10/01/2019 16:49

thanks pass the pigs x

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nojellybabies · 10/01/2019 16:50

thanks purple.

DS1 is most impressed by mumsnet now. I'll have to name change so he can't discover my secrets!

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TheSilveryPussycat · 10/01/2019 17:02

I took so long to post that thread overtook me...

BaconMaker · 10/01/2019 17:10

Don't worry too much about missing the difference of two squares. For questions like this you can have a check list in your mind.

  1. go for the highest power of x (or whatever variable is being used) and take that outside the bracket (factorise). So in this case we have a common factor of x^3.

  2. Then look for any numerical factors (for example in the denominator we have a common factor of 3)

  3. Look at any remaining expression that you suspect might still be able to factorise. Usually this will be either the difference of two squares or a quadratic equation which can be factorised.

For example you might have 2x4 - 4x3 -30x2 = First take out a factor of x2 = x2(2x2 - 4x - 30x) . Then take out another factor of 2 = 2x2(x2 - 2x - 15). Then look at the remaining quadratic equation - can it be factorised? Yes! = 2x^2(x+3)(x-5). WE now have three factors none of which can be factorised any further

nojellybabies · 10/01/2019 18:52

Thank you Bacon Flowers

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