Question:

Math question...please help :(?

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The area of a square with side 2x-1 is 49. Find x.

(2x-1)^2 = 4x^2+1=49 = 4x^2=48

ok now im stuck, then what do you do? btw ^2 means squared.

THANK YOU!

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5 ANSWERS


  1. If the square has area 49, it has side sqrt(49) = 7

    so 2x - 1 = 7

    x  = 4

    you could do it the hard way too

    (2x - 1)² = 49

    4x² - 4x + 1 = 49

    4x² - 4x - 48 = 0

    x² - x - 12 = 0

    (x+3)(x-4) = 0

    x = -3, 4


  2. 2x-1=7

    x=4

  3. woa, slow down the square root of 49 is 7 therefore:

    2x-1 = 7

    2x = 8

    x = 4

    also (2x-1)^2 = 4x^2 - 4x + 1   NOT 4x^2 + 1

  4. (2x-1)^2 is actually,

    4x^2 - 4x +1

    (a-b)^2=a^2 - 2ab + b^2

    4x^2 - 4x + 1=49

    =4x^2 - 4x - 48=0           (Quadratic Equation)

    (4x-16)(x+3)= 0

    leading to, x= 4 or -3(which is rejected as it is not possible)

    therefore x = 4

  5. If the area = 49, one side must be its root.

    Root of 49 = 7.

    therefore one side, 2x - 1 = 7

    2x = 7+1 = 8

    so x = 8/2

           = 4

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