Math

"Solving a system involving three unknowns."


3d+e-2f=-14
2d-3e+4f=-23
5d+4e-10f=-13

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  1. 1st times 3 plus the 2nd ---> 11d -2f = -65
    1st time 4, subtract the 3rd -->7d + 2f = -43

    add these last two ----> 18d = -108
    d = -6

    in 7d + 2f = -43
    -42 + 2f = -43
    2f = -1
    f = -1/2

    in the 1st:
    -18 + e -2(-1/2) = -14
    e = 3

    check in
    2nd: LS = -12 -9 - 2 = -23 = RS
    3rd: LS = -30 +12 + 5 = -13 = RS

    My answer is correct.
    d=-6
    e=3
    f=-1/2

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    posted by Reiny

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