Posted by Angie on Sunday, March 22, 2009 at 4:06pm.
sure, first find the slope
slope = (-8+2)/(9-4) = -6/5
then the equation is y = (-6/5)x + b
sub in (4,-2) , or the other point
-2 = (-6/5)(4) + b
I would now multiply by 5 (since I try to avoid fractions as much as possible)
-10 = -24 + 5b
b = 14/5
so y = (-6/5)x + 14/5
No, you have to first use
y - y1 = m(x - x1) [point slope form]
and then rewrite in the form
y = mx + c [slope intercept form]
When you are given 2 points you have to find the slope first
[m = (y2 - y1)/(x2 - x1)]
then sub in the slope with either of the points in the equation in point slope form.
Hope that helps.
I'll correct myself, yes you can I didn't think of the above method by Reiny.
I never used that way before :)
It's quite useful though.
Sorry for my error
why do you have to sub in (4,-2)? why can't you use 9,-8)?
As I said, you can use either point.
I usually use the point that has the "nicer" numbers. Either point will give you the same value of b
A good idea is to then use the other point to see if the equation works.
Related Questions
math - i have more than one question so if u no any of the answers please tell ...
algebra[please check] - in questions 1 and 2, write an equation of the line in ...
algebra - Use the given conditions to write an equation for the line in point&#...
math - I have a few question so I will number them off. Please answer them for ...
math - What happens to y as x gets larger? What happens to x as y gets larger? d...
Algebra.. - HELP. Problems 4 - 7: Write an equation for the line in point/slope ...
Algebra2 - Help? Write an equation for the line in point/slope form and slope/...
math - how do i write an equation in point slope form when the slope= -1/2 and ...
MATH - Solve by finding y and graph using the slope and y-intercept: 3x-y=1 x-y=...
Math - 1. Write the equation of a line in slope-intercept form that has a slope ...
For Further Reading
