Question

Write an equation of the line, in point-slope form, that passes through the two points (-2, 15) and (9, -18)

Please explain this to me so I can jot it down in my notebook for future reference. Will medal/fan as always.

Answer 1

Find the slope first
\[\LARGE \frac{y_2-y_1}{x_2-x_1}=slope\]

Answer 2

If you need help finding the slope let me know.

Answer 3

Hold on. Let me write it. :)

Answer 4

:) ok

Answer 5

18+15 over 9-2?

Answer 6

-18, sorry.

Answer 7

-3/7 is what I got.

Answer 8

The book gives me these answer choices and I'm totally not sure.
y-2=-3(x-15)
y-2=-1/3(x+15)
y-15=-3(x+2)
y-15=-1/3(x+2)
What does the x+ a number mean? :(

Answer 9

\[\LARGE \frac{-18-15}{9--2}=slope\]
\[\LARGE \frac{-18-15}{9+2}=\frac{- 3 }{ 11 }\]

Answer 10

Oh. - 15. I did +15.

Answer 11

Well a negative + negative makes the plus sign its just 15 not -15 so its just -3 same thing with the bottom it was 9--2 right? so i just added the 2 to get 11

Answer 12

Next step
\[\huge y-y_1=m(x-x_1)\]
where
m=slope
(x1,y1)

Answer 13

I understand how the formula goes. I just haven't used it in a few years. lol. But thank you for refreshing my memory.
Anyways, I got y-15=-3/11(x-2) and that's not a choice. :( Is there another step?

Answer 14

What are your choices?

Answer 15

I have already said them above. Let me copy paste. :)

Answer 16

The book gives me these answer choices and I'm totally not sure.
y-2=-3(x-15)
y-2=-1/3(x+15)
y-15=-3(x+2)
y-15=-1/3(x+2)
What does the x+ a number mean? :(

thats what I said. My choices are those 4.

Answer 17

Like i said before the 2 is a negative 2 if two negative signs are next to each other they become postivie

Answer 18

Okay, what about the slope? It doesnt match up.. or maybe I just suck at math. lol.

Answer 19

\(\color{#0cbb34}{\text{Originally Posted by}}\) @ayeeeitskateee
I understand how the formula goes. I just haven't used it in a few years. lol. But thank you for refreshing my memory.
Anyways, I got y-15=-3/11(x-2) and that's not a choice. :( Is there another step?
\(\color{#0cbb34}{\text{End of Quote}}\)
\[\huge~\rm~y-15=-3/11(x-2) \]
\[\huge~\rm~y-15=-3/11(x-(\huge\color{red}{-}2) \]

Answer 20

Ok lets redo the slope hold on
\[\LARGE \frac{-18-15}{9--2}=slope\]
\[\LARGE \frac{-18-15}{9+2}=\frac{- 33 }{ 11 }\]

Answer 21

We can simplfy the slope (we made a mistake earlier -18-15=-33 not -3 )

Answer 22

-3?

Answer 23

for the slope?

Answer 24

Yep

Answer 25

So what would our final answer be? (which answer choice) ?

Answer 26

C. :)

Answer 27

y-15=-3(x+2)

Answer 28

Well done :)

Answer 29

Thank you so much. it's rare somebody can help as much as you did!!

Answer 30

awee :') thanks let me know if you need more help! :D

Answer 31

Will do. :)