Question

How can I make an equation in slope-intercept form for the line passing through (5, 1) and (–4, 7) ?

Answer 1

First find the slope (or average rate of change)

Answer 2

-2/3 ? @ccswims

Answer 3

switch it, -3/2

Answer 4

Are you sure?

Answer 5

-4 - 5/ 7 - 1 = -9/6 = -3/2

Answer 6

now put it in point-slope form

(y - y1) = m(x - x1)

Answer 7

Oh! Hm.

Answer 8

Do you need help with that?

Answer 9

(y - 1) = m (x - 5)

Answer 10

@ccswims ^

Answer 11

Remember, our 'm' is our slope

So plug in the slope we got earlier for 'm'

Answer 12

Oh, right!

(y - 1) = -3/2 (x - 5)

Answer 13

good, now distribute the -3/2 to x and -5

Answer 14

(y - 1) = -3/2x - (-3/2) * 5

Answer 15

Like that?

Answer 16

(y - 1) = -3/2x + 7.5

Answer 17

now add 1 to both sides

Answer 18

Okay, so what would be the next step?

Answer 19

Oh, okay!

Answer 20

y - 1 + 1 = (-3/2)x + 8.5

Answer 21

good, and -1 + 1 = 0 so...

y = -3/2x + 8.5

Answer 22

y = -3/2 + 8.5

Answer 23

yup! And now it's in point-slope form :)

Answer 24

Thanks! But the only problem is that the answer choices all say -2/3 :/ @ccswims

Answer 25

OH, nevermind, my mistake, it is -2/3

Answer 26

I did x2 - x1/y2 - y1 when it's supposed to be y2 - y1/x2 - x1

Answer 27

Here are the answer choices:

A. http://static.k12.com/calms_media/media/212500_213000/212687/1/9992ab389cca02760faf077c3afb7e376c6e9897/09_01_ST_10_ba.gif

B. http://static.k12.com/calms_media/media/212500_213000/212690/1/4ddffcf8d26ce268aca3bcf219cf545dcfbe4acf/09_01_ST_10_bd.gif

C. http://static.k12.com/calms_media/media/212500_213000/212689/1/ab47fb347f4f3e4c5f779bc6febd07f153332c60/09_01_ST_10_bc.gif

D. http://static.k12.com/calms_media/media/212500_213000/212688/1/53d5afb6f9c4b17ce0964fecb0da62801df9e4f1/09_01_ST_10_bb.gif

Answer 28

The answer choices all say 13/3 not 8.5 :( Where did we go wrong?

Answer 29

yea, instead of doing -3/2 and multiplying it to -5 it would be -2/3 * -5, the answer is

Answer 30

13/3 ?

Answer 31

It's A

Answer 32

I knew it! Well, thanks for your explanation and the help! :)