Year 12s: what will be the first way you research your future options? >>

Help - maths question

ColeNate

How would you simplify this using long division:

(x^3-8)/(3x^2-8x+4)

Reply 1

Gregorius

Original post by ColeNate

How would you simplify this using long division:

(x^3-8)/(3x^2-8x+4)

Factor top and bottom - there's a common factor sitting in there, get rid of that first.

Reply 2

ColeNate

Original post by Gregorius

Factor top and bottom - there's a common factor sitting in there, get rid of that first.

Yeah that's what they have in the mark scheme - it's a C3 Solomon question.
I was wondering if it's possible to do straight away with long division if I wasn't able to spot the factor?

Reply 3

Gregorius

Original post by ColeNate

I was wondering if it's possible to do straight away with long division if I wasn't able to spot the factor?

Well, yes. But it's harder work!

Reply 4

ColeNate

Original post by Gregorius

Well, yes. But it's harder work!

Ah, I must be doing my long division method wrong - it's not coming out the same! :s-smilie:

Reply 5

ghostwalker

Original post by ColeNate

Ah, I must be doing my long division method wrong - it's not coming out the same! :s-smilie:

wadr to Gregorius, I don't think long division is going to do any good - unless I missed something.

Simplify usually means cancel any common factors in this context.

You could notice that the numerator is a difference of two cubes, which you should be familiar with. Hence (x-2) is a factor of the top. And if you plug in "2" into the denominator you get zero there, so (x-2) is also a factor there.

PS: A more informative thread title would have been useful, together with a label of what level this is.

Reply 6

Gregorius

Original post by ghostwalker

wadr to Gregorius, I don't think long division is going to do any good - unless I missed something.

A more informative thread title would have been useful, together with a label of what level this is.