Results 1 to 7 of 7

Math Help - Find an Equation for a Line?

  1. #1
    Newbie
    Joined
    Feb 2010
    Posts
    5

    Find an Equation for a Line?

    Hi. I need help finding the slope intercept equation for this point and slope. Here is what I have so far:

    Find the slope intercept equation for the line with the indicated slope and y-intercept.
    Slope 5/7 ; y-intercept (0,4)
    Y = 5/7x+b
    4 = 5/7 (0)+ b
    4 = 5/7 + b
    5(0)/7 + b =4
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member Bacterius's Avatar
    Joined
    Nov 2009
    From
    Wellington
    Posts
    927
    Well ... basically if you have the slope m and the y-intercept c (or the point (0, c)) then the equation of the line is simply y = mx + c.

    If you have the slope and one point that is not the y-intercept, then you need to use the coordinates of the point to solve y = mx + c for c, with (x, y) the coordinates of the points ( m is known as you have the slope)
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Feb 2010
    Posts
    5
    Thank you, but I'm still not sure I understand
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Super Member Bacterius's Avatar
    Joined
    Nov 2009
    From
    Wellington
    Posts
    927
    Quote Originally Posted by EandH View Post
    Thank you, but I'm still not sure I understand
    What don't you understand ?
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Senior Member
    Joined
    Jul 2009
    From
    Melbourne
    Posts
    274
    Thanks
    4
    Easy:

    take y=mx+c

    Where m is the gradient or the slope
    and c is the y intercept.

    So you've given us the slope which is \frac{5}{7} and the y intercept is the y point where x=0.

    The co-ordinates you have given us is (0,4)... x is 0 in this so the y intercept is 4.

    Substitute:

    y=\frac{5}{7} x +4
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Super Member Bacterius's Avatar
    Joined
    Nov 2009
    From
    Wellington
    Posts
    927
    Quote Originally Posted by jgv115 View Post
    Easy:

    take y=mx+c

    Where m is the gradient or the slope
    and c is the y intercept.

    So you've given us the slope which is \frac{5}{7} and the y intercept is the y point where x=0.

    The co-ordinates you have given us is (0,4)... x is 0 in this so the y intercept is 4.

    Substitute:

    y=\frac{5}{7} x +4
    Thank you for completing 100% of his question, that will surely help him ... please people, don't answer someone's question entirely (except if it is really an awesome question), but instead give him hints or tips or a direction to follow ... otherwise he just reads brainlessly and it's not as useful

    That being said, maybe that some people *need* to be answered the whole question as an example that they can follow, so I won't go on about this.
    ____________

    By the way, you were right in your reasoning EandH, your equation was correct and the fraction actually cancels out due to the zero, leaving b = 4 (called c in both of our posts) which is correct.
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Newbie
    Joined
    Feb 2010
    Posts
    5

    thanks

    Okay, I see now. Thank you all very much. I didn't understand how to put together what I was doing so I appreciate the explaination.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 8
    Last Post: March 22nd 2011, 05:57 PM
  2. Replies: 1
    Last Post: March 18th 2011, 11:36 AM
  3. Replies: 9
    Last Post: July 31st 2009, 06:39 AM
  4. Replies: 11
    Last Post: June 2nd 2009, 07:08 PM
  5. Replies: 5
    Last Post: October 13th 2008, 11:16 AM

Search Tags


/mathhelpforum @mathhelpforum