Question

Write an equation of the line, in point-slope form, that passes through the two given points.

(-2, 15), (9, -18)

Answer 1

First thing you have to do is find the slope using the slope formula. Do you know it?

Answer 2

no idea, im really behind in this class because i thought i was gonna drop it but now i cant.

Answer 3

Ok, the formula is this:\[m=\frac{ y _{2}-y _{1} }{ x _{2}-x _{1} }\]and the y's and x's come from the points they gave you. y2 is -18, y1 is 15, x2 is 9 and x1 is -2 and you fill in your formula using those numbers.

Answer 4

thank you!

Answer 5

I'll help you. Take notes. ALWAYS the first thing you do is find the slope.

Answer 6

\[m=\frac{ -18 - 15 }{ 9-(-2) }\]Simpifying you have this:\[m=\frac{ -18 + (-15) }{ 9+2 }\]Can you do that math for me andd let me know what you get for the slope?

Answer 7

-33/11

Answer 8

yes, now reduce it. -33 is divisible by 11. What is -33 divided by 11?

Answer 9

-3

Answer 10

good! For some reason, slope is indicated by the letter "m" in our equation, which we will use in the next step. Th point-slope formula is the next step here, right after we find the slope. Do you know the point-slope formula?

Answer 11

i think its y- y1 = m(x - x1)

Answer 12

It is! Do you know how to use it using the info we have?

Answer 13

no clue haha

Answer 14

ok, no biggie. The y1 and the x1 come from ONE of the points they gave you. AND use the slope you found, -3. Do that like this: