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Stuck on problem solving quadratic equation question.

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    Hi there, struggling to understand how this question gets the answer.

    So the area of the patio is 4m x 5m = 20m^2

    The area of the whole thing would be (4 + x)(5 + x) = ? is the ? 20m^2 + 10m^2

    Expanding that gives x^2 + 9x + 20 = ?

    I'm sort of lost on how they get 4x^2 + 18x = 10
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    (Original post by jojo55)
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    Hi there, struggling to understand how this question gets the answer.

    So the area of the patio is 4m x 5m = 20m^2

    The area of the whole thing would be (4 + x)(5 + x) = ? is the ? 20m^2 + 10m^2

    Expanding that gives x^2 + 9x + 20 = ?

    I'm sort of lost on how they get 4x^2 + 18x = 10
    (4+2x)(5+2x) because theres an x on either side of the patio.
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    (Original post by NotNotBatman)
    (4+2x)(5+2x) because theres an x on either side of the patio.
    Doh!

    Now I can see it .

    Thanks.
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    (Original post by jojo55)
    Doh!

    Now I can see it .

    Thanks.
    -20 because of the patio itself
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    (Original post by an_atheist)
    -20 because of the patio itself
    Cheers .
 
 
 
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