SOLUTION: It has been a really long time since high school so I am not sure what to do or where to look to learn how to do this! Thanks Given two points (x1, y1) and (x2, y2), derive the

Question 285651: It has been a really long time since high school so I am not sure what to do or where to look to learn how to do this!
Thanks
Given two points (x1, y1) and (x2, y2), derive the equation of the line that passes through those two points and write
it in the form y = mx + b. This is called the slope-intercept form of the equation of the line because the two parameters m and b
represent the slope and y-intercept of the line.
Found 3 solutions by stanbon, Alan3354, richwmiller:
Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
Given two points (x1, y1) and (x2, y2), derive the equation of the line that passes through those two points and write
it in the form y = mx + b. This is called the slope-intercept form of the equation of the line because the two parameters m and b
represent the slope and y-intercept of the line.
----------------
slope = m = (y2-y1)/(x2-x1)
------------------------------
The line passes thru (x1,y1) so substitute the point
values and the slope values into y = mx+b to get:
y1 = {{y1-y2]/[x2-x1]}[x1] + b
b = y1 - {{y2-y1]/[x2-x1]}[x1]
b = y1 - {x1y2-x1y1}/{x2-x1}
---
b = [y1(x2-x1) - (x1y2-x1y1]/[x2-x1]
b = [x2y1-x1y1-x1y2+x1y1]/[x2-x1]
b = [x2y1-x1y2]/[x2-x1]
-------------------------------
Equation:
y = [(y2-y1)/(x2-x1)]x + [x2y1-x1y2]/[x2-x1]
=================================================
Cheers,
Stan H.
Answer by Alan3354(69443)   (Show Source): You can put this solution on YOUR website!
Given 2 points example.
Find the equation of the line thru the points (2,1) and (3,5)
---------------------
This is a 2 step process. First find the slope of the line thru the points.
slope, m = diffy/diffx
m = (5-1)/(3-2)
m = 4
---------
Now use y = mx + b with either point to find b, the y-intercept.
y = mx + b
5 = 4*3 + b
b = -7
-------
y = mx + b
y = 4x - 7 is the answer.
------------------------
For further assistance, or to check your work, email me via the thank you note.

Answer by richwmiller(17219)   (Show Source): You can put this solution on YOUR website!
You can look in your math book. What a novel idea!
You can look online.
You can go to algebra.com and have someone else do it for you.

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