Results 1 to 4 of 4

Thread: Algebra 1 - Slope help

  1. #1
    Newbie
    Joined
    Dec 2008
    Posts
    5

    Algebra 1 - Slope help

    Yea im back more help needed

    Write an equation of the line shown in each graph, please explain how to do this one and i can understand the rest sorry its sideways i took the pic with my phone

    Follow Math Help Forum on Facebook and Google+

  2. #2
    Member
    Joined
    Oct 2007
    Posts
    178
    You're looking for a line with the formula y= mx+ b , in which m= slope and b= y intercept.


    First, use the slope formula with your two points to find the slope.
    $\displaystyle \frac{y2-y1}{x2-x1}$
    That is "m."

    Next, plug one of your points, such as (-5,0) into the equation.

    0= -5m + b
    You should have m already from the slope formula. You then solve for b.

    Finally, you put it all together.

    y= mx+ b

    Alternately, to find b you can use the formula y1-y= m(x-x1), called the point-slope formula.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Dec 2008
    Posts
    5
    please explain more my head is just popping right now
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    12,880
    Thanks
    1946
    Your two points are $\displaystyle (-5, 0)$ and $\displaystyle (0, 2)$.

    You are looking for the equation of the line, i.e. $\displaystyle y = mx + c$ where m is the slope and c is the y-intercept.

    We're given the y-intercept. It's 2.

    So we just need the slope.

    Here, $\displaystyle x_1 = -5, y_1 = 0, x_2 = 0, y_2 = 2$.

    So using the slope of a line formula

    $\displaystyle y = \frac{y_2 - y_1}{x_2 - x_1} = \frac{2 - 0}{0 - -5} = \frac{2}{5}$.

    So the equation of the line is

    $\displaystyle y = \frac{2}{5}x + 2$, or if you want to clean it up...

    $\displaystyle 5y - 2x - 10 = 0$.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 6
    Last Post: Sep 11th 2011, 04:53 PM
  2. Replies: 2
    Last Post: Sep 16th 2009, 08:13 PM
  3. Replies: 10
    Last Post: Jul 30th 2009, 06:54 PM
  4. Slope/Graph--Algebra ?'s
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: Sep 14th 2007, 10:49 AM
  5. Basic Algebra: Finding Slope
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: Aug 30th 2007, 01:22 PM

Search Tags


/mathhelpforum @mathhelpforum