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Homework Help: Simulataneous equation with surds

  1. Oct 6, 2007 #1
    Im trying a question from one of my text books which asks me to solve simultaneously:

    5x-3y = 41 and (7√2)x + (4√2)y = 82

    Ive tried elimination and substitute methods but the surds confuse me so i would appreciate it if anyone can come up with some guidelines of how i should approach this question.

  2. jcsd
  3. Oct 6, 2007 #2

    D H

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    Staff Emeritus
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    There is nothing special about the surds. Two suggestions if they confuse you:
    • Replace the coefficients [itex]7\surd2[/itex] and [itex]4\surd2[/itex] with named parameters such as a and b. Solve and then replace a and b with the known values.
    • Multiply both sides of the second equation by [itex]\surd2[/itex].
  4. Oct 6, 2007 #3


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    Science Advisor

    Numbers are numbers! Just go ahead and solve the equations the way you would if there were no "surds". For example, you could multiply the second equation by 3 and multiply the first equation by 4[itex]\sqrt{2}[/itex], then add the equations to eliminate y.
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