Algebra I: Calculating equation of a line from point and slope
This is a free lesson from our course in Algebra I
 
   
This lesson explains how to write the equation of a line if you know its slope and a point on it. This form of equation of a line is called the point-slope form. As you'll see, equation of a line with slope m and passing through a point (a, b) is given by 
                          y - b = m(x - a)
Somewhere, you'll find a point as (x1, y1) and a slope m, and a formula:
y y1 = m(x x1)
Here subscripts are just intended to indicate the point given.
You have the generic "x" and generic "y" that are always in your equation, and then you have the specific x and y from the point given; the specific x and y are what is subscripted in the formula. (More text below video...)
<h2>Algebra I - Calculating equation of a line from point and slope</h2> <p>equation, line, slope, point, , calculating, finding, online math, passing, through, practice questions, point slope, quizzes</p> <p>Equation of a line with slope m and passing through a point (a, b) is given by y - b = m(x - a)</p>
Other useful lessons:
Calculating equation of a line from two points
Calculating equation of a line from slope and intercept
Calculating equation of a line from point and intercept
Determine whether a point lies on a line
(Continued from above) For example : Find the equation of the straight line that has slope m = 4 and passes through the point (1,1).
You've given m = 4, x1 = 1, and y1 = 1.
You'll plug these values into the point-slope form, and solve for "y=":
y y1 = m(x x1)
y (1) = (4)(x (1))
y -1 = 4(x - 1)
y - 1 = 4x - 4
y = 4x - 4 + 1
y = 4x 3
Winpossible's online math courses and tutorials have gained rapidly popularity since their launch in 2008. Over 100,000 students have benefited from Winpossible's courses... these courses in conjunction with free unlimited homework help serve as a very effective math-tutor for our students.
- All of the Winpossible math tutorials have been designed by top-notch instructors and offer a comprehensive and rigorous math review of that topic.
- We guarantee that any student who studies with Winpossible, will get a firm grasp of the associated problem-solving techniques. Each course has our instructors providing step-by-step solutions to a wide variety of problems, completely demystifying the problem-solving process!
- Winpossible courses have been used by students for help with homework and by homeschoolers.
- Several teachers use Winpossible courses at schools as a supplement for in-class instruction. They also use our course structure to develop course worksheets.
 
       
     
 Copyright © Winpossible, 2010 - 2011
Best viewed in 1024x768 & IE 5.0 or later version