Question

What is the equation in point-slope form of the line passing trhough (0,2) and (1,5)?

y - 5 = 3(x-1)
y - 2 = -3(x-0)
y +2 = 3(x+1)
y + 5 = -3(x+1)

I solved the equation using point slope form for a linear equation and I did it twice, one for each set of coordinates and I got A and B. I just don't know which one to choose that'll be right since I got both answers.

Help please?

Answer 1

find the slope first.....slope(m) = (y2 - y1) / (x2 - x1)
(0,2).....x1 = 0 and y1 = 2
(1,5)...x2 = 1 and y2 = 5

slope(m) = (5 - 2) / (1 - 0)
slope(m) = 3/1 or just 3

Now use point slope form
y - y1 = m(x - x1)
slope (m) = 3
you can use either of your points
using (0,2).....x1 = 0 and y1 = 2
y - y1 = m(x - x1)
y - 2 = 3(x - 0)

using (1,5)...x1 = 1 and y1 = 5
y - y1 = m(x - x1)
y - 5 = 3(x - 1)

so your only possible answers are :
y - 2 = 3(x - 0) and y - 5 = 3(x - 1)

so B is not correct because the 3 is not negative
understand ?

Answer 2

Ops, sorry. I knew that it wasn't B - I meant to say it's either A or C. The answers I got were...
y - 2 = 3(x-0) ---> that was for the corrdinates (0,2)
y - 5 = 3(x-1) ---> that was for coordinates (1,5)

I just don't know what to do know since I can't have two answers.

Answer 3

anything with a -3 as the slope will not work. Thus leaving only 2 answer choices...and 1 of them is y + 2....not an answer choice. So A is the only correct one.

Answer 4

I mean, in your answers that you arrived at....there is no y + 2...so C is wrong

Answer 5

Wait a minute. It's A, sorry. I've been looking at numbers for too long. I got mixed up.
Thanks for helping me out :)