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    Question 22 on Edexcel July 2016 Higher, can't figure it out even looking at the answers. The answer should be 2 and 6.
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    (Original post by billcs)
    Question 22 on Edexcel July 2016 Higher, can't figure it out even looking at the answers. The answer should be 2 and 6.
    Yeah, so what part of the solution is confusing exactly?

    EDIT: I assume the answers give the full working out, if not, then attempt it yourself and post your working here if you get stuck.
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    x^2 = 4 (x-3)(x-3)
    expand the brackets and multiply the terms by 4, you should be able to do the rest.
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    [Full solution removed]
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    (Original post by billcs)
    Question 22 on Edexcel July 2016 Higher, can't figure it out even looking at the answers. The answer should be 2 and 6.
    It might help you to write (x-3)^2 as (x-3)(x-3).
    Expand then multiply everything by 4, then rearrange to get as a quadratic that you can solve.
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    (Original post by badmathkid)
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    Part of the rules of the forum is that we don't post full solutions to questions asked. Please remove yours.
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    Okay, what have you learnt so far? There are two equations equal to each other. What should your first step be? Also, any working out you have done, please post it here so we can see what you are struggling with and then we can help you.
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    (Original post by billcs)
    Question 22 on Edexcel July 2016 Higher, can't figure it out even looking at the answers. The answer should be 2 and 6.
    Here are the steps:

    1.) calculate the square term (x-3)² on the right side first.
    2.) multiply this calculated square term by 4.
    3.) subtract x² on each side of the equation
    4.) divide by 3 to get a simple quadratic equation.
    5.) solve this equation by pq-formula to get your values for x.

    If you do those right, it has to be x1 = 2 and x2 = 6
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    (Original post by billcs)
    Question 22 on Edexcel July 2016 Higher, can't figure it out even looking at the answers. The answer should be 2 and 6.
    Do you know that a^2b^2=(ab)^2 from that we know that 4(x-3)^2=2^2(x-3)^2=
    (2x-6)^2. Therefore, x^2=(2x-6)^2. Does this help you?
 
 
 

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