Turn on thread page Beta
    • Thread Starter
    Offline

    16
    ReputationRep:
    https://youtu.be/pOH13db9qi0?t=5m41s

    I know this is pretty basic stuff but could someone explain why on the numerator he gets  4(x-2)(2x+5) and not  4(x-2)^2(2x+5) and so on?
    • Community Assistant
    Offline

    20
    ReputationRep:
    Community Assistant
    (Original post by AxSirlotl)
    https://youtu.be/pOH13db9qi0?t=5m41s

    I know this is pretty basic stuff but could someone explain why on the numerator he gets  4(x-2)(2x+5) and not  4(x-2)^2(2x+5) and so on?
    Because theres already an (x-2) in the denominator, so you have to multiply top and bottom by a factor (same as multiplying by 1) that makes the common denominator essentially.
    Offline

    11
    ReputationRep:
    The first term is:

     \dfrac{4}{x-2}.

    To place over a common denominator:

     (x-2)^{2} (2x+5),

    we need:

     \dfrac{4}{(x-2)}\, \ast \, \dfrac{(x-2)(2x+5)}{(x-2)(2x+5)}.

    Does this help? :-)
    • Thread Starter
    Offline

    16
    ReputationRep:
    (Original post by NotNotBatman)
    Because theres already an (x-2) in the denominator, so you have to multiply top and bottom by a factor (same as multiplying by 1) that makes the common denominator essentially.
    (Original post by simon0)
    The first term is:

     \dfrac{4}{x-2}.

    To place over a common denominator:

     (x-2)^{2} (2x+5),

    we need:

     \dfrac{4}{(x-2)}\, \ast \, \dfrac{(x-2)(2x+5)}{(x-2)(2x+5)}.

    Does this help? :-)
    Ok thanks, I think I understand now
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: October 10, 2017

University open days

  • University of East Anglia
    UEA Mini Open Day Undergraduate
    Fri, 23 Nov '18
  • Norwich University of the Arts
    Undergraduate Open Days Undergraduate
    Fri, 23 Nov '18
  • Edge Hill University
    All Faculties Undergraduate
    Sat, 24 Nov '18
Poll
Black Friday: Yay or Nay?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

Equations

How to use LaTex

Writing equations the easy way

Equations

Best calculators for A level Maths

Tips on which model to get

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.