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Square root algebra problem? ?

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sq. rt 7x +29 =x+3 Find all or real imaginary soluctions to the equation

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  1. if the question is √(7x+29)=x+3

    Square both sides;

    7x+29=x²+6x+9

    0=x²-x+20

    0=(x+4)(x-5)

    x=-4 or x=5

    If the question is (√(7x))+29=x+3, then first subtract 29 from both sides before squaring both sides.

    _/


  2. im assuming the whole left side is sqrted:

    sqrt(7x + 29) = x + 3

    square both sides:

    7x + 29 = (x + 3)^2

    expand the squared bracket using FOIL or the distributive law:

    7x + 29 = x^2 + 3x + 3x + 9

    7x + 29 = x^2 + 6x + 9

    take it all to one side:

    0 = x^2 + 6x + 9 - 7x -29

    0 = x^2 - x - 20

    now, you either factorise, or if this is too difficult, use the quadratic equation to solve for 'x'. in this case, it is easy to factorise:

    0 = (x + 4)(x - 5)

    therefore, (because one bracket must be zero for the product to be 0) either

    x + 4 = 0

    x = -4

    OR

    x - 5 = 0

    x = 5

    so, the solutions are, (both real) -4 and 5.

    subbing them back in, it works:

    for x=-4:

    sqrt(7*-4 + 29) = -4 + 3

    sqrt(-28 + 29)  = -1

    sqrt (1)           = -1

    1 = -1 ^ 2

    1 = 1

    LHS = RHS

    :)

  3. (x+4) (x-5) The solutions are -4 and 5.

  4. square both sides and solve.

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