Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    0
    ReputationRep:
    Sorry if this is super obvious, but I have a number of algebra questions to solve. I know if the question was y-7=4 you'd simply add 7 to both sides, but can you do the same if it's 7-y? If not, can someone talk me through this please?
    Offline

    2
    ReputationRep:
    Add y to both sides then see what happens
    Offline

    15
    ReputationRep:
    There are several ways to solve this. Let's try one.

    7 - Y = 4

    try adding y to both sides.

    in that case you get

    7 - y + y = 4 + y


    the ys cancel and you are left with 7 = 4 +y

    minus 4 from both sides...
    you get
    y = 3

    make sense?
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by Law-Hopeful)
    Add y to both sides then see what happens
    7-y = 4
    7= 4 + y
    3 = + y
    y = 3

    Like so? Sorry no maths for a few weeks has shrunk my brain it seems ! :P
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by Temporality)
    There are several ways to solve this. Let's try one.

    make sense?
    Yes, thank you so much!
    Offline

    2
    ReputationRep:
    (Original post by Winterfellrises)
    7-y = 4
    7= 4 + y
    3 = + y
    y = 3

    Like so? Sorry no maths for a few weeks has shrunk my brain it seems ! :P
    That's right.
    Offline

    3
    ReputationRep:
    oh my god I miss GCSEs so much.
    Offline

    3
    ReputationRep:
    If it was 7-y=4 (think of it as -y+7=4)

    The you would need to eliminate the +7 so you would subtract -7 from both side so -y=-3 and y=3.


    An alternative way of managing the numbers is to move the numbers across the equals sign so you end up with y=… and when you move a number or letter over you change the sign so a +7 becomes a -7 when you move it across.
    Offline

    1
    ReputationRep:
    Is it not just blindingly obvious that if you start with 7, end with 4, and you had to take a value (y) away to get there, then it's clearly 3?

    Although I guess you may need to show working of some sort, and in any case I haven't done algebra for 7 years
    • Thread Starter
    Offline

    0
    ReputationRep:
    Just thought I'd say to the sarcastic comments, I'm not actually a GCSE student, I just posted here because I know it's GCSE material.
    Offline

    18
    ReputationRep:
    If you can't answer that question your to young to be watching game of thrones OP
 
 
 
  • 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
    Will you be richer or poorer than your parents?
    Useful resources

    Study tools

    Rosette

    Essay expert

    Learn to write like a pro with our ultimate essay guide.

    Thinking about uni already?

    Thinking about uni already?

    See where you can apply with our uni match tool

    Student chat

    Ask a question

    Chat to other GCSE students and get your study questions answered.

    Creating

    Make study resources

    Create all the resources you need to get the grades.

    Planner

    Create your own Study Plan

    Organise all your homework and exams so you never miss another deadline.

    Resources by subject

    From flashcards to mind maps; there's everything you need for all of your GCSE subjects.

    Papers

    Find past papers

    100s of GCSE past papers for all your subjects at your fingertips.

    Help out other students

    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.