|
Question 478211: Find an equation of the line that contains the given of points (23,27)(5,9)
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! Find an equation of the line that contains the given of points (23,27)(5,9)
-------------
Determinants is the best way.
--------
|+x +y +1|
|23 27 +1| = 0
|+5 +9 +1|
The +'s are for alignment
------
x*(27-9) - y*(23-5) + 23*9-5*27 = 0
18x - 18y = -72
x - y = -4
--------------------
If you're not familiar with determinants:
Find the slope, m = diffy/diffx
(23, 27)
( 5, 9)
--------- Subtract
18, 18
m = 18/18 = 1
-------------
Use y = mx + b and either point to find b, the y-intercept
9 = 1*5 + b
b = 4
------
--> y = x + 4
Same equation, different form
|
|
|
| |
