The Student Room Group

Maths Alevel

image-c09c7b0c-56fd-4920-8390-ac7edfb09cd41793652579-compressed.jpg.jpeg
how to do number 15 part 2??? how can x^3-8x-13 be (2x^3+2)/(3x^2-2)?
Reply 1
Original post by deviany
image-c09c7b0c-56fd-4920-8390-ac7edfb09cd41793652579-compressed.jpg.jpeg
how to do number 15 part 2??? how can x^3-8x-13 be (2x^3+2)/(3x^2-2)?

If you multiply out the fraction, i.e. bring 3x^2-2 to the left and multiply it by the x, then rearrange, you should see that it gives you the original equation :smile:
Original post by Unlucki
If you multiply out the fraction, i.e. bring 3x^2-2 to the left and multiply it by the x, then rearrange, you should see that it gives you the original equation :smile:


what do u mean by multiply it by the x?
Reply 3
Original post by deviany
what do u mean by multiply it by the x?

As the previous post suggested, multiplying through by the denominator gives
x(3x^2-2) = 2x^3+2
Rearrange it and you get back to your original cubic equation.

Quick Reply

Latest