Turn on thread page Beta

can someone good at maths please point me in the right direction? watch

Announcements
    • Thread Starter
    Offline

    1
    ReputationRep:
    I'm doing the number grid coursework for gcse maths, and I need to prove that the difference between two products is always 10. How do I go about doing this? I haven't a clue, and it's due in tomorrow
    Any help would be greatly appreciated!
    Offline

    2
    ReputationRep:
    (Original post by Cate)
    I'm doing the number grid coursework for gcse maths, and I need to prove that the difference between two products is always 10. How do I go about doing this? I haven't a clue, and it's due in tomorrow
    Any help would be greatly appreciated!
    elucidation required.
    • Thread Starter
    Offline

    1
    ReputationRep:
    (Original post by Ralfskini)
    elucidation required.
    Sorry! OK, you have to multiply the top left number in 2X2 box on a 10x10 number grid by the bottom right number, and vice versa, then calculate the difference between these two products. I have found that the product is always 10, but I don't know how to prove this.
    The formula for the overall products of the box is, I think, 2nsquared + 22n + 10
    Offline

    0
    ReputationRep:
    I was teaching this to year 8's the other week!

    Hold on whilst I work it out.....

    Ok.

    GRID:

    n | n+1
    -------------
    n+10 | n+11

    Product will always be:

    n*(n+11) = n^2 + 11n

    and

    (n+10)*(n+1) = n^2 + 11n + 10


    Difference = (n^2 + 11n + 10) - (n^2 + 11n)
    = n^2 - n^2 + 11n - 11n + 10
    = 10

    Thus proved. Ok?
    Offline

    2
    ReputationRep:
    I did actually type out a complete solution to this problem but thanks to the ******* server it didnt let me post it.
    • Thread Starter
    Offline

    1
    ReputationRep:
    Thanks for your help! As it happens though, by the time the stupid server let me view the thread, I had figured it out anyway :rolleyes: Cheers anyway

    (Original post by Ralfskini)
    I did actually type out a complete solution to this problem but thanks to the ******* server it didnt let me post it.
    Why don't you try copying it before posting? Also, if you press refresh on the 'server is too busy screen' sometimes it will keep your post.
    • Thread Starter
    Offline

    1
    ReputationRep:
    Lol, I can't believe I couldn't figure that out, I feel really stupid now :rolleyes: Hehe...
 
 
 
Poll
Do you think parents should charge rent?
Useful resources

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.