Turn on thread page Beta
    • Thread Starter
    Offline

    1
    ReputationRep:
    2x+y=1
    x^2+y^2=1

    rearranged eq 1 which is y=1-2x
    sub into eq 2 which is x^2+(1-2x)^2=1
    which is 5x^2-4x+1=1
    then you have to make it quad by moving 1 left
    5x^2-4x+1-1 which cancels the 1's out which leaves it 5x^2-4x? dont get it
    Please help if u can! Much appreciated
    Offline

    5
    ReputationRep:
    you've done all the hard work!

    You can factor out the x giving x(5x-4) = 0 then x = 0 or 4/5

    When x = 0 y = 1 when x = 4/5 y = -3/5
    Offline

    18
    ReputationRep:
    (Original post by YsfAli)
    2x+y=1
    x^2+y^2=1

    rearranged eq 1 which is y=1-2x
    sub into eq 2 which is x^2+(1-2x)^2=1
    which is 5x^2-4x+1=1
    then you have to make it quad by moving 1 left
    5x^2-4x+1-1 which cancels the 1's out which leaves it 5x^2-4x? dont get it
    Please help if u can! Much appreciated
    You have forgotten the '= 0'; taking away 1s from both sides leaves you with 5x^2 - 4x = 0, which is easy to factorise. As skeptical_john said, you've done the hard work already.
    • Thread Starter
    Offline

    1
    ReputationRep:
    (Original post by skeptical_john)
    you've done all the hard work!

    You can factor out the x giving x(5x-4) = 0 then x = 0 or 4/5

    When x = 0 y = 1 when x = 4/5 y = -3/5
    yes i didnt think of that. was just thinking of putting it in the form of ax^2+b+c. Thanks!
    btw is 2(3x)^2 18x or 12x? Thanks!
 
 
 

University open days

  1. University of Bradford
    University-wide Postgraduate
    Wed, 25 Jul '18
  2. University of Buckingham
    Psychology Taster Tutorial Undergraduate
    Wed, 25 Jul '18
  3. Bournemouth University
    Clearing Campus Visit Undergraduate
    Wed, 1 Aug '18
Poll
How are you feeling in the run-up to Results Day 2018?

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.