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Math Help - simplify..need help

  1. #1
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    simplify..need help

    Hello ,
    I need some king person to show me how to finish off my question,

    in the picture attached the correct answer is in green in the bottom corner, I cant seem to get it?
    Please
    Attached Thumbnails Attached Thumbnails simplify..need help-presproblem.jpg  
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  2. #2
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    Hope this helps

    Did you apply the distributive law when you multiplied the first equation.

    4*(1-x^2)^(1/2) + 2*x(1-x^2)^(-1/2)*(-2*x)

    Then, your common denominator was correct. But you would end up with this,

    numerator: (4*(1-x^2) - 4*x^2)

    denominator: ((1-x^2)^(1/2))

    I don't know how to do all the code, but if you apply the distributive law you should end up with what is in green; if unclear let me know.
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  3. #3
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    Hello
    I am not sure how to do the distributive law?
    Can you tell/show please?
    Thanks
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  4. #4
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    The distributive law is like this.

    say we have x(y + z)

    then, x(y+z) = xy + xz and if it were like this (y + z)x = yx + zx.

    So, an example would be like this....say we have the following:

    2(x-4) = 2x - 8. What you are doing is you are taking the 2 and multiplying each of the elements in parentheses by it.

    Another example:
    3(y + 8) = 3y + 24
    5(z - 3) = ? (Think about this one)
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  5. #5
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    Quote Originally Posted by mesmo View Post
    Did you apply the distributive law when you multiplied the first equation.

    4*(1-x^2)^(1/2) + 2*x(1-x^2)^(-1/2)*(-2*x)

    Then, your common denominator was correct. But you would end up with this,

    numerator: (4*(1-x^2) - 4*x^2)

    denominator: ((1-x^2)^(1/2))

    I don't know how to do all the code, but if you apply the distributive law you should end up with what is in green; if unclear let me know.
    Hello, 5(z - 3) =5z -15
    Yes I understand the law,I didnt know what you meant

    The part I am mixed up with is (4*(1-x^2) - 4*x^2)
    How do I still have 1-x^2 in the numerator? Did I not put it in the denominator?
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  6. #6
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    Quote Originally Posted by wolfhound View Post
    Hello, 5(z - 3) =5z -15
    Yes I understand the law,I didnt know what you meant

    The part I am mixed up with is (4*(1-x^2) - 4*x^2)
    How do I still have 1-x^2 in the numerator? Did I not put it in the denominator?
    You did put it in the denominator. But remember what you put in the denominator

    (1-x^2)^(1/2)...

    .Once that is in the denominator, in order to create like denominators for everything you have to multiply the other term by (1-x^2)^1/2 and when you multiply it by the other one, you'll end up with (1-x^2)....

    remember (1/2) + 5...in order to add these, we need like denominators so we multiply the 5 by 2 and put that over 2. which will yield (1/2) + (10/2)....
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