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Math Help - Sketch the line

  1. #1
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    Sketch the line

    Hi,
    I have the straight line equation of, 2x+3y-12=0. I need to sketch the line but I'm not really sure how to do this so I require some help please!

    Thanks!
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  2. #2
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    Re: Sketch the line

    Quote Originally Posted by andyboy179 View Post
    Hi,
    I have the straight line equation of, 2x+3y-12=0. I need to sketch the line but I'm not really sure how to do this so I require some help please!

    Thanks!
    Rearrange into the form y = mx+c and then plot it. m is the gradient and (0,c) is a point on the line

    To plot a line you need two points. I suggest using (0,c) and (t,0) where t is the value that makes y=0
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  3. #3
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    Re: Sketch the line

    Quote Originally Posted by andyboy179 View Post
    Hi,
    I have the straight line equation of, 2x+3y-12=0. I need to sketch the line but I'm not really sure how to do this so I require some help please!

    Thanks!
    One way to do this is to rewrite the general equation to a linear equation you are more familiar with y = mx + b, where m is the slope and b is the y intercept.

    2x + 3y - 12 = 0
    3y = -2x + 12
    y = (-2/3)x + 4

    can you take it from here? EDIT: -1 was faster than I was.
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  4. #4
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    Re: Sketch the line

    Thanks for the posts!!
    I understand up to this point however when it comes to the graph I tknow where I would plot the (-2,3) but I don't understand the slope part. How would I draw this?
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  5. #5
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    Re: Sketch the line

    Quote Originally Posted by andyboy179 View Post
    Thanks for the posts!!
    I understand up to this point however when it comes to the graph I tknow where I would plot the (-2,3) but I don't understand the slope part. How would I draw this?
    start at the y-intercept (0,4) ... slope is rise/run, -2/3 ... down 2 , right 3
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  6. #6
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    Re: Sketch the line

    Oh I see! Thanks!
    Do you know how I would be able to find the co-ordinates of A and B?
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  7. #7
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    Re: Sketch the line

    Quote Originally Posted by andyboy179 View Post
    Oh I see! Thanks!
    Do you know how I would be able to find the co-ordinates of A and B?
    what do you mean? what are points A and B?
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  8. #8
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    Re: Sketch the line

    I'm not too sure, I just have to fine the co ordinates of A and B. I wasn't sure that's why I asked.
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    Re: Sketch the line

    Quote Originally Posted by andyboy179 View Post
    I'm not too sure, I just have to fine the co ordinates of A and B. I wasn't sure that's why I asked.
    what are A and B ? cite the problem in its entirety.
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  10. #10
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    Re: Sketch the line

    After sketching the line where the 2x+3y-12=0 cuts the x axis at A and the y axis at B, find the coordinates of A and B.
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  11. #11
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    Re: Sketch the line

    Quote Originally Posted by andyboy179 View Post
    After sketching the line where the 2x+3y-12=0 cuts the x axis at A and the y axis at B, find the coordinates of A and B.
    A is the x-intercept ... where y = 0

    B is the y-intercept ... where x = 0 (you already know this set of coordinates)
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  12. #12
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    Re: Sketch the line

    So A's coordinates are (0,4) and B's coordinates are (7,0)?
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  13. #13
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    Re: Sketch the line

    Quote Originally Posted by andyboy179 View Post
    So A's coordinates are (0,4) and B's coordinates are (7,0)?
    no

    2x+3y = 12

    A is the x-intercept (y = 0) ... 2x + 3(0) = 12 ... solve for x

    B is the y-intercept ... come on Andy, look at post #5. pay attention, son.
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  14. #14
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    Re: Sketch the line

    So A's coordinates are (0,6) and B's coordinates are (0,4)?
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    Re: Sketch the line

    Quote Originally Posted by andyboy179 View Post
    So A's coordinates are (0,6) and B's coordinates are (0,4)?
    Again, no- but your error may just be a typo. When x= 0, you calculated that y= 12/3= 4 so (0, 4) is a point. When y= 0, x= 12/2= 6 but x is always the first member of the pair- the other point is (6, 0), not (0, 6).
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