Solve For x...5

Discussion in 'Other Pre-University Math' started by nycmathguy, Apr 9, 2022.

  1. nycmathguy

    nycmathguy

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    Revisiting precalculus just for fun.
    Enjoy.

    IMG_20220409_181615.jpg
     
    nycmathguy, Apr 9, 2022
    #1
  2. nycmathguy

    MathLover1

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    1-(a/b)(1-a/x)-(b/a)(1-b/x)=0

    1-(a/b)((x-a)/x)-(b/a)((x-b)/x)=0

    1-(a(x-a))/(bx)-(b(x-b))/(ax)=0..........common denominator is abx, multiply both sides

    abx-a^2(x-a)-b^2(x-b)=0

    abx-a^2*x+a^3-b^2*x+b^3=0

    abx-a^2*x-b^2*x=-a^3-b^3....isolate x

    x(ab-a^2-b^2)=-(a^3+b^3)

    x=-(a^3+b^3)/(ab-a^2-b^2).........(ab-a^2-b^2)=-(a^2-ab+b^2)

    x=-(a^3+b^3)/-(a^2-ab+b^2)............cancel minuses and factor a^3+b^3=(a + b) (a^2 - a b + b^2)

    x=((a + b) (a^2 - a b + b^2))/(a^2-ab+b^2)......simplify

    x=a + b
     
    MathLover1, Apr 9, 2022
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  3. nycmathguy

    nycmathguy

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    Don't you just love precalculus? Do you miss the course?
     
    nycmathguy, Apr 9, 2022
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    MathLover1 likes this.
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