Hey there! Sign in to join this conversationNew here? Join for free

Help! Maths! Watch

Announcements
    • Thread Starter
    Offline

    7
    ReputationRep:
    I'm not sure if I've done it correctly, so I wanted to double check the answer. The question is as follows:
    w,x and y are three integers
    w is 2 less than x
    y is 2 more than x
    Prove that wy + 4 =x^2
    Offline

    13
    ReputationRep:
    so w = x -2
    y = x+2
    Set wy + 4 = L.H.S. and try to work it through from there!
    the thread title made me laugh lol, reminds me of my first year at college
    • Thread Starter
    Offline

    7
    ReputationRep:
    (Original post by k.russell)
    so w = x -2
    y = x+2
    Set wy + 4 = L.H.S. and try to work it through from there!
    the thread title made me laugh lol, reminds me of my first year at college
    The way I did it was by giving x a value of 1, and worked on from there, would that be correct? So w became -1 and y became 3
    • Community Assistant
    • Welcome Squad
    Offline

    19
    ReputationRep:
    (Original post by Botcampers)
    I'm not sure if I've done it correctly, so I wanted to double check the answer. The question is as follows:
    w,x and y are three integers
    w is 2 less than x
    y is 2 more than x
    Prove that wy + 4 =x^2
    w=x-2

    y=x+2

    wy=(x-2)(x+2)

    Expand. Rearrange.
    Offline

    13
    ReputationRep:
    (Original post by Botcampers)
    The way I did it was by giving x a value of 1, and worked on from there, would that be correct? So w became -1 and y became 3
    no need to plug in numbers! this is algebra m8 no numbers allowed (apart from coefficients). In all seriousness, the substitution you should be making is to get y and w in terms of x then rearrange to prove that what you have is = to x^2
    Offline

    2
    ReputationRep:
    Hi, this is my solution to your question.

    w = x-2
    y = x+2
    wy - (x-2)(x+2) - Difference of two squares
    - x^2 - 2^2
    - x^2 - 4
    wy + 4 = x^2 - 4 + 4
    4s cancel it out so is just x^2

    Hope that helped!!
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Should Spain allow Catalonia to declare independence?
    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

    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
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • 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

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