Results 1 to 11 of 11

Math Help - algebra - expand - simplify - solve - rearrange help!

  1. #1
    Newbie
    Joined
    Feb 2009
    Posts
    21

    algebra - expand - simplify - solve - rearrange help!

    can you show some workings too please that would be great


    1) (q+4)(q+5) expand and simplify i got - q(squared)+9q+20

    simplified 9q(cubed) + 20

    2) expand and simplify (2k - 3m)(3k+2m) help?

    3) Solve 5(x+1)=3x + 12

    4)facotorise x(squared) + 5x + 4

    5) rearrange the forumla to make x the subject y = b- ax(squared)

    5) solve x(squared) + 5x + 4 = 0
    Last edited by gilzean; February 10th 2009 at 09:15 AM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Senior Member mollymcf2009's Avatar
    Joined
    Jan 2009
    From
    Charleston, SC
    Posts
    490
    Awards
    1
    Quote Originally Posted by gilzean View Post
    can you show some workings too please that would be great


    1) (q+4)(q+5) expand and simplify i got - q(squared)+9q+20

    simplified 9q(cubed) + 20

    You can't combine q^2 and 9q, they have different powers (you multiplied them), leave it in the quadratic form
    . By simplifying it means combine all your like terms, like 5q & 4 q

    2) expand and simplify  (2k - 3m)(3k+2m) help?

    F.O.I.L. First. Outer. Inner. Last

    6k^2 + 4km - 9km -6m

    = 6k^2 - 5km -6


    3) Solve 5(x+1)=3x + 12

    First, distribute your 5 through (x+1) to get 5x +5 = 3x + 12. Then solve for x

    4)facotorise x(squared) + 5x + 4

    What two numbers, when added together give you 5 AND when multiplied together give you 4? (x+1)(x+4) right?

    5) solve x(squared) + 5x + 4 = 0

    You will have two answers. See #4. You can either factor it like I did above or use the quadratic equation to get your answers.
    Got it now?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Feb 2009
    Posts
    21
    i dont think so because they are year 11 maths questions :S and i think oyur doing complex stuff with them im confussseeed
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Senior Member mollymcf2009's Avatar
    Joined
    Jan 2009
    From
    Charleston, SC
    Posts
    490
    Awards
    1
    If this is for a high school algebra class, then this is pretty basic algebra. Not sure how else to explain it to you. What are you confused on?
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Feb 2009
    Posts
    21
    (2k - 3m)(3k+2m) surely would be 6K(squared) - 2km - 6m
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Newbie
    Joined
    Feb 2009
    Posts
    21
    so..factorising x(squared) + 5x + 4 actually = what?
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Newbie
    Joined
    Feb 2009
    Posts
    21
    it would really really help if you wrote out the answer for eaccchh showing the working like i know u did for number one but the rest would help
    Follow Math Help Forum on Facebook and Google+

  8. #8
    Senior Member mollymcf2009's Avatar
    Joined
    Jan 2009
    From
    Charleston, SC
    Posts
    490
    Awards
    1
    Quote Originally Posted by gilzean View Post
    (2k - 3m)(3k+2m) surely would be 6K(squared) - 2km - 6m

    (2k-3m)(3k+2m)

    FOIL
    First: (2k)(3k) = 6k^2

    Outer: (2k)(2m) = 4km

    Inner: (-3m)(3k) = -9km

    Last: (-3m)(2m) = -6m^2

    6k^2 + 4km - 9km -6m^2

    Combine like terms:

    6k^2 - 5km - 6m^2

    Sorry I left out the m^2 somewhere in my first post.

    Is that more clear?
    Follow Math Help Forum on Facebook and Google+

  9. #9
    Senior Member mollymcf2009's Avatar
    Joined
    Jan 2009
    From
    Charleston, SC
    Posts
    490
    Awards
    1
    Quote Originally Posted by gilzean View Post
    so..factorising x(squared) + 5x + 4 actually = what?
    x^2 + 5x + 4

    (x+4)(x+1)

    x = -4 and x = -1

    Factoring is the reverse of FOILing. FOIL gets rid of factors and puts it into quadratic form. Factoring is undoing FOIL.
    Follow Math Help Forum on Facebook and Google+

  10. #10
    Newbie
    Joined
    Feb 2009
    Posts
    21
    thanks alot , **** i left out the = 0 , x(squared) + 5x + 4 = 0 does that matter?
    Follow Math Help Forum on Facebook and Google+

  11. #11
    Senior Member mollymcf2009's Avatar
    Joined
    Jan 2009
    From
    Charleston, SC
    Posts
    490
    Awards
    1
    Quote Originally Posted by gilzean View Post
    thanks alot , **** i left out the = 0 , x(squared) + 5x + 4 = 0 does that matter?
    Well if you don't have an equal sign, you aren't really solving it, you would just be evaluating it. So since you need to find an answer for "x", yes you should have that =0 in there.

    Ok? Good job sticking with it!
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Need algebra to simplify/solve an equation
    Posted in the Algebra Forum
    Replies: 5
    Last Post: August 28th 2011, 07:02 PM
  2. Expand and simplify
    Posted in the Algebra Forum
    Replies: 9
    Last Post: March 12th 2010, 04:18 PM
  3. Expand and simplify help?
    Posted in the Algebra Forum
    Replies: 6
    Last Post: October 30th 2009, 08:48 AM
  4. Expand and Simplify
    Posted in the Algebra Forum
    Replies: 2
    Last Post: June 16th 2009, 02:25 PM
  5. expand and simplify
    Posted in the Algebra Forum
    Replies: 4
    Last Post: November 9th 2008, 08:00 AM

Search Tags


/mathhelpforum @mathhelpforum