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Thread: graphing question

  1. #1
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    graphing question

    need help Solve the system of equations below by graphing them with a pencil and paper. Enter your answer as an ordered pair.

    y = 2x - 3
    y = -2x + 5
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  2. #2
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    Quote Originally Posted by daniel323 View Post
    need help Solve the system of equations below by graphing them with a pencil and paper. Enter your answer as an ordered pair.

    y = 2x - 3
    y = -2x + 5
    I mean you could just plot them out using...

    $\displaystyle y = mx + b$

    ...where $\displaystyle m$ is the slope and $\displaystyle b$ is the intercept.

    Or, add the equations like so:

    $\displaystyle y = 2x - 3 $
    $\displaystyle \underline{y = -2x + 5}$

    $\displaystyle 2y = 2 \implies \fbox{y=1}.$

    So, subbing $\displaystyle y=1$ back into your first equation gives

    $\displaystyle (1) = 2x-3 \implies \fbox{x=2}.$

    The answer is $\displaystyle (2,1).$
    Last edited by Anonymous1; May 6th 2010 at 02:09 PM.
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  3. #3
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    how ??
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  4. #4
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    Choose some $\displaystyle x$ values to plug in to both equations, then find the corresponding $\displaystyle y$ values:

    $\displaystyle \underline{x}$ $\displaystyle \underline{y}$

    $\displaystyle 1$ ..

    $\displaystyle 2$ ..

    $\displaystyle 3$ ..

    Then, plot these coordinates on a graph for both equations.

    You want the point at which the two lines intersect.
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  5. #5
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    it was incorrect
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  6. #6
    Super Member Anonymous1's Avatar
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    Quote Originally Posted by daniel323 View Post
    it was incorrect
    Check again. I wrote "x=2" and "y=1" but accidentally wrote "(1,2)." The answer is (2,1).
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  7. #7
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    i got it wrong i cant go back to it its online test
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  8. #8
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    it was 2,1
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