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Math Help - substitution by system of equations

  1. #1
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    substitution by system of equations

    3y + x = -1
    2x+6=-5y
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  2. #2
    A riddle wrapped in an enigma
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    Quote Originally Posted by daniegirl View Post
    3y + x = -1
    2x+6=-5y
    1. Solve first equation for x to get x = -1-3y

    2. Substitute that value for x into the second equation and solve for y:

    2(-1-3y)+6=-5y
    -2-6y+6=-5y
    4 = y

    3. Substitute y = 4 into first equation to solve for x:

    3(4) + x = -1
    12 + x = -1
    x = -13
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