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Thread: Checking points

  1. #1
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    Checking points

    My teacher told me to do this for homework, and taught some students on how to solve it by equation but did not teach me.

    Check whether the given points is or is not the point of intersection for the lines.

    (6,16)

    y= 3x-2
    y= 5x -12

    All I remember from the teacher teaching my friend was.

    3x-2=5x-12
    3x-5x=-12+2
    -2x=10
    --- ---
    -2 -2
    x= -5

    What do I do with the -5? 0.0
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  2. #2
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    Equations intersect when they are equal. That is, when

    3x-2=5x-12

    Solving, we get x=5.

    Thus, they intersect at (5,13)
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  3. #3
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    What is the full calculation to see if the point is intersecting or not?
    I need this for a test, please help.
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  4. #4
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    Quote Originally Posted by buck View Post
    What is the full calculation to see if the point is intersecting or not?
    I need this for a test, please help.
    That is the calculation--you set the two equations equal to eachother and solve for x. Once you have x (in this case, 5) you plug it into either equation and will get the y value (in this case, 13). Then you know where it intersects. As you can see, this does not match the point you were given. So it does not intersect there.
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