math

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solve with substitution
5x - y=-1
15x=2y

  • math -

    solve the first equation for y.
    5x-y=-1 subtract 5x from both sides
    -y=-1-5x divide by -1
    y=1+5x

    now, plug this answer in for y in the second equation.
    15x=2y
    15x=2(1+5x)
    15x=2+10x
    5x=2
    x=.4

    plug this(x=.4) into the equation for y.
    y=1+5x
    y=1+5(.4)
    y=1+2
    y=2

    therefore, x=.4 and y=2 or (.4, 2)

  • math -

    actually that does not work out, plug x and y into original equation...

  • math -

    actually that does not work out, plug x and y into original equation...
    y=1+2
    y=3

    then it works out

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