- advertisement -

Algebra

Discussion in 'Parents Off Topic' started by KeltonsMom, Jan 22, 2009.

  1. KeltonsMom

    KeltonsMom Approved members

    Joined:
    Sep 12, 2007
    Messages:
    3,605
    I swear Kelton's Algebra is going to be the death of me in a few minutes..


    Kelton needs some help on this:


     
  2. czardoust

    czardoust Approved members

    Joined:
    Oct 16, 2007
    Messages:
    2,178
    a-2b = 2
    a-2b+2b=2+2b
    a=2+2b


    a+b = 2 (b+3)
    2+2b+b=2(b+3)

    2+3b=2b+6
    2+3b-3b=2b-3b+6
    2-6=-b+6-6
    -4=-b
    -1 -1
    4=b

    a-2b=2
    a-2(4)=2
    a-8=2
    a-8+8=2+8
    a=10

    does that help cause if a-2b=2 then 10-8=2 and 10+4=2(4+3)
    14=14

    done :)
     
  3. BozziesMom

    BozziesMom Approved members

    Joined:
    Jul 16, 2008
    Messages:
    3,863
    It's killing me too...
     
  4. misscaitp

    misscaitp Approved members

    Joined:
    Jul 26, 2007
    Messages:
    1,121
    Doing the linear combination method you basically try to eliminate a variable using two equations so:

    1. a-2b=2
    a+b=2(b+3)

    2. So you are going to want to get a top variable to equal a bottom variable so I decided to eliminate the a variable and to do that you multiply the bottom equation by -1

    a-2b = 2
    -a-b=-2(b+3)

    3. So then you add together the top and bottom equation so you should get:

    -3b=-2b-4

    4. Simplify that down to:

    -b=-4

    5. So b=4

    6. And after that you can just plug in 4 for b and solve for a. Or you can solve it the linear combination method. Either way you get a=10
     
  5. Karenwith4

    Karenwith4 Approved members

    Joined:
    Dec 2, 2007
    Messages:
    1,442
    So what you want to do is isolate for one unknown so you end up with a=whatever and that there are no a's on the other side of the = sign.

    then you can plop the "whatever" part of the equation into where ever it saya a...because you know what a equals.


    So
    a-2b = 2

    isolate the a by adding 2b to each side of the equation in order to keep it even on both sides
    a - 2b (+2b) = 2 (+2b)

    reduce the left side (ie the -2b and the +2b cancel each other out) so now you have:
    a=2 + 2b

    Now you know what a equals. Use that in the second equation and substitute (2+2b) for a (i'm using brackets to try to show you the substitutions)

    starting equation
    a+b = 2 (b+3)

    substitute in a=2+2b
    (2+2b)+b= 2 (b+3)

    collect like variables
    2+3b=2(b+3)

    here you are multiplying 2 across the brackets
    2+3b=2xb + 2x3

    do multiplication
    2+3b= 2b +6

    (subtract 2b from both sides to keep it even)
    2+ 3b-2b=2b+6-2b

    collect like variables and do addition/subtraction
    2+ 1b=6

    (subtract 2 from both sides to isolate the varriables)
    2+ 1b-2 =6-2

    do addition/subtraction
    1b=4
    b=4

    you can check by subsituting b=4 back into the equation where you had only bs
    (2+2b)+b= 2 (b+3)

    czardoust shows the check.

    hth
    Karen
     
  6. KeltonsMom

    KeltonsMom Approved members

    Joined:
    Sep 12, 2007
    Messages:
    3,605
    Thank you to all of you for your help..I had Kelton look at this thread and he then said "oh yeah" Good thing he knows what you all wrote down, because once I saw the first a= my brain shut down :eek:
     
  7. czardoust

    czardoust Approved members

    Joined:
    Oct 16, 2007
    Messages:
    2,178

    LMAO....thats like me and my oldest daughter with her Algebra 2 & Trig homework

    Tangents, sins and co-sins! YAH right.:D
     
  8. diamondback688

    diamondback688 Approved members

    Joined:
    Oct 9, 2006
    Messages:
    1,650
    This probably doesn't help, but just wait until he gets to college.:D:D:p:p:eek::eek:
     
  9. KeltonsMom

    KeltonsMom Approved members

    Joined:
    Sep 12, 2007
    Messages:
    3,605
    By that time I will be a walking zombie and he will just have to rely on tutors or by asking the professor for help.:p
     
  10. Illinifan

    Illinifan Approved members

    Joined:
    Feb 15, 2007
    Messages:
    1,405
    Trig's a snap. You just have to remember Chief Sohcahtoa.

    Sin = opposite over hypotenus
    Cosin = adjacent over hypotenus
    Tangent = opposite over adjacent
     
  11. KeltonsMom

    KeltonsMom Approved members

    Joined:
    Sep 12, 2007
    Messages:
    3,605
    I want your email address, that way I can email you Algebra problems LOL
     
  12. Illinifan

    Illinifan Approved members

    Joined:
    Feb 15, 2007
    Messages:
    1,405
    My 18 year old starts tutoring a college sophomore tomorrow for her Algebra class. It's good practice for him since he wants to teach HS math.

    I can find out if he can squeeze you in. ;)
     

Share This Page

- advertisement -

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice