algebra

-2x - 2y = 6
y = 3x -5

-2x -2(3x=17)=6
-2x-6x-34
-8x-34=6
=34=34
-8x=40
x=5

is this right?

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  1. L J,so it looks like you are dealing with systems of equations.
    I'll solve it for you real quick below.

    -2x- 2y = 6
    y = 3x - 5

    The best method to use is to solve with substitution.

    Step 1:
    Write the equations.
    y = 3x - 5
    -2x- 2y = 6

    Step 2: Solve for Y in y = 3x - 5
    Notice that Y is already given, which is 3x - 5,
    so:
    Step3:Substitute 3x - 5 for y in -2x- 2y = 6
    -2x - 2y = 6
    -2x - 2(3x - 5) = 6
    -8x + 10 = 6
    Step 4: Isolate -8x
    -8x+ 10 - 10 = 6 - 10
    -8x= -4
    Step 5: Isolate x further by dividing by -8 on both sides
    -8x / -8 = -4 / -8
    x = 1/2. So no, X is not equal to 5.

    We also need to solve for Y. Since we got X = 1/2, substitute 1/2 for X in either equation, preferably the original (or first) equation.
    y = 3x - 5
    y = 3(1/2) - 5
    Simplify
    y = -7/2

    Therefore, x = 1/2, and y= -7/2 OR (1/2, -7/2)

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  2. I didn't check the whole calculation, but
    -8x=40
    x=5
    is certainly wrong.

    You can easily check to see whether your answer is correct. Just use it! If x=5,
    -2*5 - 2y = 6
    -10-2y = 6
    -2y = 16
    y = -8

    y = 3*5 -5
    y = 15-5 = 10

    Clearly that is not the correct value for x.

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