We're supposed to write an equation for the line. So, like, for question #9 on the sheet, we pulled the points (4, 4) and (2,0 ) off the line. Then we wrote out our y=mx+b equation. And to figure out m, we did delta Y over delta X, and got +2. So now the equation was y=2x+b. And to get b, we did 0=2 multiplied by 2 + b, which is 0= 4 +b, so b= -4. So then our equation was y=2x-4. So if my two points are (-2, 5) and (2, -3) how would I do this equation?
2007-09-23 12:03:20 · 2 answers · asked by "Spencer" 3 in Education & Reference ➔ Homework Help
Wow, you lost me too, sorry.
2007-09-23 12:16:02 · answer #1 · answered by Zuker 5 · 0⤊ 0⤋
Lets do the delta y over delta x:
m = (y2-y1)/(x2 - x1)
m = (5 - (-3))/(-2 -2)
m = 8/(-4)
m = -2
So now the equation is:
y = -2x + b
Now you can use either point and plug into the x and y, lets use (-2,5):
y = -2x + b
5 = -2(-2) + b
5 = 4 + b
1 = b
So your equation is:
y = -2x + 1
2007-09-23 19:59:33 · answer #2 · answered by jsardi56 7 · 0⤊ 0⤋