Easy method for adding or taking away algebraic equations?

Maths and statistics discussion, revision, exam and homework help.

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  1. amani-puresapphire's Avatar
    • Peer Of The TSR Realm
    • Location: Oxford
    • Posts: 1,918
    Easy method for adding or taking away algebraic equations?
    Hi

    Could someone please remind me how to add or take away algebraic equations? Im revising for C3 (Differentiation) and I seem to struggle with the last step of answering questions.

    For example, how to take away:

    ( (2x−1)^2 X 6x ) − (3x^2 X 4(2x−1) )


    I've left it in the above form because thats how its written in the solution I have but I cant work out why the answer is:

    6x(2x−1)[(2x−1)−2x]


    Sorry this seems to be a basic thing but I cannot remember how to do it. Im on a gap year and decided to do this A2 maths course so I dont have a teacher at this moment.

    Thanks in advance!
  2. raheem94's Avatar
    • TSR Demigod
    • Posts: 5,512
    Re: Easy method for adding or taking away algebraic equations?
    (Original post by amani-puresapphire)
    Hi

    Could someone please remind me how to add or take away algebraic equations? Im revising for C3 (Differentiation) and I seem to struggle with the last step of answering questions.

    For example, how to take away:

    ( (2x−1)^2 X 6x ) − (3x^2 X 4(2x−1) )


    I've left it in the above form because thats how its written in the solution I have but I cant work out why the answer is:

    6x(2x−1)[(2x−1)−2x]


    Sorry this seems to be a basic thing but I cannot remember how to do it. Im on a gap year and decided to do this A2 maths course so I dont have a teacher at this moment.

    Thanks in advance!
     6x(2x-1)^2 - 3x^2 \times 4(2x-1) = 6x(2x-1)^2 - 12x^2(2x-1)

    Now pull out,  6x(2x-1) , as a common factor.
  3. Intriguing Alias's Avatar
    • TSR Idol
    • Location: Yorkshire
    Re: Easy method for adding or taking away algebraic equations?
    (Original post by amani-puresapphire)
    Hi

    Could someone please remind me how to add or take away algebraic equations? Im revising for C3 (Differentiation) and I seem to struggle with the last step of answering questions.

    For example, how to take away:

    ( (2x−1)^2 X 6x ) − (3x^2 X 4(2x−1) )


    I've left it in the above form because thats how its written in the solution I have but I cant work out why the answer is:

    6x(2x−1)[(2x−1)−2x]


    Sorry this seems to be a basic thing but I cannot remember how to do it. Im on a gap year and decided to do this A2 maths course so I dont have a teacher at this moment.

    Thanks in advance!
    Find a common factor in each.

    E.g. 6x(3x+2) - 7(3x+2)² = (3x+2)(6x) - (3x+2)(3x+2)(7) = (3x+2)(6x - 7(3x+2)) = (3x+2)(-15x - 14)
  4. amani-puresapphire's Avatar
    • Peer Of The TSR Realm
    • Location: Oxford
    • Posts: 1,918
    Re: Easy method for adding or taking away algebraic equations?
    (Original post by raheem94)
     6x(2x-1)^2 - 3x^2 \times 4(2x-1) = 6x(2x-1)^2 - 12x^2(2x-1)

    Now pull out,  6x(2x-1) , as a common factor.
    Thank you both soooo much! I cannot believe I didnt think of asking on here sooner.
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