MATH

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I NEED TO SOLVE FOR Y AND X
im getting rele confused on this. ok here is the prob.

x+y=5
x-2y=-4

equation 1 x+y=5
equation 2 x-2y=-4

Multiply equation 1 by -1.
Add equation 1 to equation 2. The x term cancels. Solve for y.

THEN, put the value of y into either equation and solve for x.

Finally, put the value of x and y into the OTHER equation and see if those values satisfy the equation.

  • MATH -

    Multiplying Equation 1 by -1 you get:

    -x-y=-5

    Adding that to equation 2 you get:

    -x -y = -5
    + x -2y = -4
    -------------------
    -3y = -9
    Divide both sides by -3 and you get
    y=3
    Put that back into either equation and you can solve for x
    x+y=5
    x+3=5
    x+3-3=5-3
    x=2
    So x=2, y=3 should be the solutions.
    Check this in the other equation, x-2y=-4
    2-2(3) = -4
    2-6 = -4 why yes it does! :-)

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