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algebra

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3x+5y=0 2x-5y=-9

idk how 2 solve it then graph it my teacher eont help me plzz help

  • algebra -

    I assume you need to solve these equations simultaneously ?

    3x + 5y = 0
    2x - 5y = -9

    Solving by elimination method. The object is to eliminate one of the variables, either x or y.

    Since you have +5y in the first equation and -5y in the second equation, you ADD the two equations.
    This is because +5y + -5y = 0.

    3x + 5y = 0
    2x - 5y = -9
    5x + 0 = -9
    5x = -9
    Divide both sides by 5
    x = -9/5

    To find y, substitute x = -9/5 in either equation and solve for y.
    3x + 5y = 0
    x = -9/5
    3(-9/5) + 5y = 0
    -27/5 + 5y = 0
    Add 27/5 to both sides
    -27/5 + 27/5 + 5y = 27/5
    5y = 27/5
    Divide both sides by 5
    y = 27/5 /5
    Multiplying the numerator by the reciprocal of the denominator is the same as dividing.

    y = 27/5 * 1/5
    y = 27/25

    I'll leave the check to you.
    x = -9/5, y = 27/5

  • algebra -

    o ok ty

  • algebra -

    You're welcome.

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