x+6y=27 7x-3y=9 por metodo de igualacion

Question

x+6y=27
7x-3y=9 por metodo de igualacion

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Mia 2 weeks 2021-09-11T01:07:48+00:00 1 Answer 0

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    2021-09-11T01:09:35+00:00

    Answer:

    (3,4)

    Step-by-step explanation:

    The system of equations is:

    x+6y=27

    7x-3y=9.

    I looked up “metodo de igualacion”. It is basically American for doing substitution.

    However, the only difference is you are asked to solve both equations for a variable.

    The first equation looks easy to solve for x. So I’m going to solve both equations for x.

    x+6y=27

    Subtract 6y on both sides:

    x     =-6y+27

    7x-3y=9

    Add 3y on both sides:

    7x    =3y+9

    Divide both sides by 7:

    x     =3/7 y +9/7

    So both equations are solved for x.  You want to find when the x’s are the same because you are looking for a common amongst the lines given.

    So we have

    -6y+27=3/7 y  +9/7

    I hate the fractions honestly so I’m going to multiply both sides by 7 so they will no longer be for now:

    -42y+189=3y + 9

    Now add 42y on both sides:

             189=45y+9

    Subtract 9 on both sides:

            180=45y

    Divide both sides by 45:

                4=y

    If 4=y, then y=4.

    So now once we have obtain 4 for y, we will use one of the equations given along with it to find x. Just choose one. Choose the easier looking one to you.

    I like the x=-6y+27 with y=4.

    So replace y with giving you:

    x=-6(4)+27

    x=-24+27

    x=3

    So the solution is (x,y)=(3,4).

    x=3 and y=4.

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