Results 1 to 6 of 6

Math Help - Slope-Intercept

  1. #1
    Newbie
    Joined
    Jan 2008
    Posts
    4

    Slope-Intercept

    I have to get this weekend homework done quick! My parents come home in about 6 hours and it HAS to be done before that! I'm suppose to "Write the slope-intercept form of an equation of the line that passes through the given point and is parallel to the graph of each equation." I really don't understand the y=mx+b formula and I know it has a big part in the problems. I'm given a line and the slope-intercept equation of it and I think my teacher said all it was for is to take the slope from it and then use the two coordinates given (-2,-3) to plug in and have a line parallel to the first one. If someone can explain to me where the numbers go in the formula, I should be able to work the other problems. Here is #1: y=2x-1 and the given point is (-2,-3). So where does 2,-2,and -3 go in the y=mx=b formula??
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Aug 2007
    From
    USA
    Posts
    3,111
    Thanks
    2
    I have to get this weekend homework done quick! My parents come home in about 6 hours and it HAS to be done before that! I'm suppose to "Write the slope-intercept form of an equation of the line that passes through the given point and is parallel to the graph of each equation." I really don't understand the y=mx+b formula and I know it has a big part in the problems. I'm given a line and the slope-intercept equation of it and I think my teacher said all it was for is to take the slope from it and then use the two coordinates given (-2,-3) to plug in and have a line parallel to the first one. If someone can explain to me where the numbers go in the formula, I should be able to work the other problems. Here is #1: y=2x-1 and the given point is (-2,-3). So where does 2,-2,and -3 go in the y=mx=b formula??
    You need more tools in your bag of tricks.

    I really don't understand the y=mx+b formula
    Then I think you're sunk. You need this. If you don't get this one, how are you going to understand the "Point-Slope" form, the "2-Point" form, the "Standard Form", or the "Intercept Form"?

    You say you have a teacher. That's a good start. Have you also a book? There MUST be some background information in there.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Jan 2008
    Posts
    4
    Yes I have a teacher and a book. But when she taught this, I didn't get it and then she assigned weekend homework. If you could just tell me where those numbers plug into the formula, then I could work the rest of them. The sheet has an equation and a line on a graph representing it. Then there is a point to the left of it and it's position is (-2,-3). I have to figure out the equation for a line parallel to the first using the slope of the first one and the coordinates of the point. So the three numbers I have are: 2 -the slope of the first equation, and (-2,-3) which are the coordinates of the point. I have to plug these three numbers into y=mx=b and that is the answer. I just don't know where each number goes. I think I remember my teacher saying you plug a number into y,m,x, and then b remains as it is without being replaced by a number. So where do the three numbers go in the formula?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by leedownen View Post
    I have to get this weekend homework done quick! My parents come home in about 6 hours and it HAS to be done before that! I'm suppose to "Write the slope-intercept form of an equation of the line that passes through the given point and is parallel to the graph of each equation." I really don't understand the y=mx+b formula and I know it has a big part in the problems. I'm given a line and the slope-intercept equation of it and I think my teacher said all it was for is to take the slope from it and then use the two coordinates given (-2,-3) to plug in and have a line parallel to the first one. If someone can explain to me where the numbers go in the formula, I should be able to work the other problems. Here is #1: y=2x-1 and the given point is (-2,-3). So where does 2,-2,and -3 go in the y=mx=b formula??
    Let your line be y = mx + c. It has to be parallel to the line y = 2x - 1. But parallel lines have the SAME gradient and the gradient of y = 2x - 1 is 2. Therefore m = 2.

    So your line becomes y = 2x + c. How do we get c??? Well, you know that (-2,-3) is a point on your line, that is, when y = -3, x = -2:

    -3 = 2(-2) + c.

    So you can solve for c: c = 1.

    Then your line becomes y = 2x + 1 and that's the answer.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Jan 2008
    Posts
    4
    One more question! When you solved for c, the problem was -3=2(-2)+c! how do you solve all those numbers to equal 1??

    edit: (for the second time!) Oh! I think I get it. Is this correct?
    -3=2(-2)+c
    -3=-4+C
    move 4 to right side of equal sign and it the problem is 1=c
    Last edited by leedownen; January 5th 2008 at 02:58 PM. Reason: question
    Follow Math Help Forum on Facebook and Google+

  6. #6
    MHF Contributor
    Joined
    Aug 2007
    From
    USA
    Posts
    3,111
    Thanks
    2
    Quote Originally Posted by leedownen View Post
    move 4 to right side of equal sign and it the problem is 1=c
    You MUST step up your game a little, here. It is not acceptable to "move" things. Try addition.

    -3 = -4 + c

    -3 + 4 = -4 + 4 + c

    1 = 0 + c = c

    No kidding, if you stick to more fundamentally correct behavior, you will learn more, you will be prepared better for the future, and you will be more consistent.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. how does m = b (or slope=y-intercept
    Posted in the Advanced Statistics Forum
    Replies: 2
    Last Post: February 15th 2011, 08:27 AM
  2. Help with slope and y-intercept
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: March 27th 2007, 11:34 PM
  3. slope and y-intercept.
    Posted in the Pre-Calculus Forum
    Replies: 4
    Last Post: March 21st 2007, 09:58 AM
  4. slope-intercept
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: September 27th 2006, 12:11 AM
  5. Slope & Y-Intercept
    Posted in the Advanced Algebra Forum
    Replies: 1
    Last Post: March 28th 2005, 10:10 PM

Search Tags


/mathhelpforum @mathhelpforum