Algebra

Solve by elimination method.
7r-3s=14
3r+7s=64

Could never figure out the elimination method. Would love some help with this one. Thanks

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  1. 21r - 9s = 42
    (I multiplied the first eq. by 3)
    21r + 49s = 448
    (I multiplied the second equation by 7)

    58s = 406
    (I subtracted the third equation from the fourth, to eliminate r.)

    The remaining steps are easy.

    s = 7

    7r -21 = 14
    r = 5

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    posted by drwls

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