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Help with simultaneous equations?

  • 17-12-2008 06:39PM
    #1
    Cow Moolester
    Closed Accounts Posts: 256 ✭✭


    Hola :)

    I got a Christmas exam tomorrow and need some help with simlutaneous equations as I was out while we were doing them. The equation is:
    x+y=-1
    2x-z=-2
    y+3z=10

    So do I just insert 0x, 0y and 0z where appropriate? I did that but it still doesn't work out :(

    Also any help with this one?

    4y-2= 5x
    3 2

    18x-20y=3

    I know that I multiply the top by 2 and 3 but do I multiply the bottom equation also?

    Thanks :)


Comments

  • #2
    Sherifu
    Registered Users, Registered Users 2 Posts: 17,727 ✭✭✭✭Sherifu


    From eq 3:
    y=10-3z

    Sub into eq1 and solve with eq2:
    x+(10-3z)=-1
    2x-z=-2

    solve from there I imagine...


  • #3
    Cow Moolester
    Closed Accounts Posts: 256 ✭✭Cow Moolester


    I love you! It worked out!


  • #4
    MathsManiac
    Registered Users, Registered Users 2 Posts: 1,595 ✭✭✭MathsManiac


    For your second problem, you need to multiply both sides of the first equation by 6.


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