Question

A line contains the points (3, –2) and (–6, –8). Write the equation of the line using point-slope form.

Answer 1

Do you know the formula to find the slope of a line given 2 points?

Answer 2

y=mx+b ?

Answer 3

\[m=\frac{ y _{2}-y _{1} }{ x _{2}-x _{1} }\]

Answer 4

The formula you gave above is the slope-intercept form of a line.

Answer 5

First let's find the slope using the points. Fill in the formula like this to find the slope:

Answer 6

i got -10/9 is that right ?

Answer 7

\[m=\frac{ -8-(-2) }{ -6-3 }\]

Answer 8

Actually, no, that's incorrect. -8-(-2) is the same thing as -8+2, so the numerator, or the rise of that slope is -6

Answer 9

The run, or the denominator, is -9

Answer 10

So the slope is \[\frac{ -6 }{ -9 }\]
which can be reduced and simplified to \[\frac{ 2 }{ 3}\]

Answer 11

oh i see

Answer 12

So the slope is 2/3

Answer 13

The formula for point-slope is as follows:

Answer 14

\[(y-y _{1})=m(x-x _{1})\]

Answer 15

You found the "m", the slope, now use ONE of the given points to complete the point-slope equation for a line. If you use the first point of (3, -2), your equation will look like this:
\[(y-(-2))=\frac{ 2 }{ 3 }(x-3)\]

Answer 16

Simplified you get:
\[(y+2)=\frac{ 2 }{ 3 }(x-3)\]

Answer 17

If you use the other point, you will get:
\[(y-(-8))=\frac{ 2 }{ 3 }(x-(-6))\]

Answer 18

Which simplifies to
\[(y+8)=\frac{ 2 }{ 3 }(x+6)\]

Answer 19

I'm going to revert in part of this message to all capitals just to make a point and hopefully it will help you make some sense out of this, so please don't be offended at all caps here...

Answer 20

no i wont not at all thank you so much for the help i really appreciate it a lot

Answer 21

What you need to understand as a students is that EVEN THOUGH THE EQUATIONS ARE DIFFERENT FROM EACH OTHER, THEY REPRESENT THE EXACT SAME LINE BECAUSE BOTH THOSE POINTS ARE ON THE SAME LINE!!! Using one or the other will be correct.

Answer 22

thank you

Answer 23

Any time!!!