Question

Find the equation in slope-intercept form of the line through points (-2, 5) and (6, -15).

How would i do this? Do i use y = mx+b? or what im not sure how to do it

Answer 1

ya use y=mx+b

Answer 2

do you know how to figure out the slope?

Answer 3

No ;-;

Answer 4

okay so it will be change in y over change in x

Answer 5

I mean i was asking cause i was trying to search how to do it and some would say y = mx+b and then some would be solving it like this
(-2,5) and (6, -15)
First find slope. (m) (y2-y1)/(x2-x1)
m=(-15-5)/(6-2)

Answer 6

ya you are doing it right so far

Answer 7

so then when you find m you use a set o your points to find b.

Answer 8

do you want me to show you?

Answer 9

wait so like this?
(-2,5) and (6, -15)
First find slope. (m) (y2-y1)/(x2-x1)
m=(-15-5)/(6-2)
m=-20/4 is the slope
now replace x and y terms (y = mx+b)
5=-20/4*2+b?
is that correct so far?

Answer 10

x2 -x1 = 6 - (-2) so it becomes 6 + 2

Answer 11

oh.. so
(-2,5) and (6, -15)
First find slope. (m) (y2-y1)/(x2-x1) x2 -x1 = 6 - (-2) so it becomes 6 + 2
m=(-15-5)/(6+2)
m=-20/8 is the slope
now replace x and y terms (y = mx+b)
5=-20/8*2+b?

Answer 12

so the slope is -20/8 = -5/2
using one of the given points, (x1, y1) and (x,y)
y-y1 = -5/2(x-x1)

Answer 13

This is how a certain site said to do it :/
(-2,5) and (6, -15)
First find slope. (m) (y2-y1)/(x2-x1) x2 -x1 = 6 - (-2) so it becomes 6 + 2
m=(-15-5)/(6+2)
m=-20/8 is the slope
now replace x and y terms (y = mx+b)
5=-20/8*2+b?

5=-40/8+b
5+40/8=b
(40+40)/8=b
80/8=b the y intercept
Thus equation being
y=-20x/8+80/8

Answer 14

@Nick88888888 you don't need a site to tell you to always reduce to the lowest term

Answer 15

hmm... not quite.
First you want to find the slope (m)
So, use the formula:

Then you want to use the formula:
y = mx + b (this is your point-intercept formula)
Use (-2, 5) where (x,y) therefore x = -3, y = 5 and we know m(slope) = -20/8
Therefore:
\[y=mx + b \rightarrow 5= -20/8 \times-2 +b \]

From here, multiply everything by 8 to get rid of the fraction:
5*8 = -20(-2) + 8b
40 = 40 + 8b

Subtract 40 from both sides,
40 - 40 = 40 + 8b - 40
0 = 8b
Find the value of b by dividing both sides by 8 and we get
b = 0

Then plug this into your formula:
y= mx + b , where we now know the value of m and b :)