Question

What is the equation of the line that contains the points (3, –6) and (–3, 0)?

Answer 1

A.
y = x – 3
B.
y = –x – 3
C.
y = –x + 3
D.
y = x + 3

Answer 2

lets find the slope first
slope(m) = (y2 - y1) / (x2 - x1)
(3,-6) x1 = 3 and y1 = -6
(-3,0) x2 = -3 and y2 = 0
now we sub
slope(m) = (0 - (-6) / (-3-3)
slope(m) = (0 + 6) / -6
slope(m) = 6/-6 which is -1

now we use y = mx + b and find b
slope(m) = -1
you can use either of your sets of points
(3,-6) x = 3 and y = -6
now we sub again
-6 = -1(3) + b
-6 = -3 + b
-6 + 3 = b
-3 = b
so your equation is : y = -x - 3

Do you have any questions ?

Answer 3

yeah can you help me on this one too?? What is the equation of the line that passes through the points (0, 5) and (2, 3)?

Answer 4

find the slope..
slope(m) = (y2 - y1) / (x2 - x1)
(0,5) x1 = 0 and y1 = 5
(2,3) x2 = 2 and y2 = 3
now sub
slope(m) = (3 - 5) / (2 - 0)
can you find the slope from here ?

Answer 5

2?

Answer 6

check again....
slope(m) = -2/2
now what does -2/2 = ??

Answer 7

1

Answer 8

-1

Answer 9

it equals -1. So our slope = -1.

now we will use y = mx + b and we are looking for b
slope(m) = -1
you can use either of your set of points
(2,3) x = 2 and y = 3
now we sub
y = mx + b
3 = -1(2) + b
can you solve for b from here ?

Answer 10

b=5

Answer 11

3 = -1(2) + b
3 = -2 + b
3 + 2 = b
5 = b
correct
so our equation is : y = -x + 5
Do you see how I got the equation ?

Answer 12

omg thanks!! can you help me with another one ??

Answer 13

I suppose...what ya got ?

Answer 14

What is the slope of the line represented by the equation below? y= -2/3x+3

Answer 15

In y = mx + b form, the slope is in the m position.
Look at your equation....y = -2/3x + 3
what number is in the m position ?

Answer 16

-2/3

Answer 17

correct....so your slope is -2/3

Answer 18

another one?

Answer 19

lets see it :) We can work on it together

Answer 20

What is the slope of the line that passes through the points (1, 1) and (–1, –5)?

Answer 21

use the slope formula
slope = (y2 - y1) / (x2 - x1)
(1,1) x1 = 1 and y1 = 1
(-1,-5) x2 = -1 and y2 = -5
now sub
slope = (-5 - 1) / (-1-1)
can you finish and find the slope ?

Answer 22

hello ??

Answer 23

im doing it

Answer 24

sorry...I did not mean to rush you

Answer 25

3

Answer 26

-6/-2 = 3
you are correct...the slope is 3

Answer 27

see..you can do this...you are smart :)

Answer 28

nahh i dont think so......... can you help me with another one ?

Answer 29

of course

Answer 30

What is the equation of the line that has a slope of -1/3 and a y-intercept of 5/2?

Answer 31

think about it....In y = mx + b form, the m is your slope and the b is your y intercept.
Can you write the equation now ?

Answer 32

i dont know this one

Answer 33

slope = -1/3
y intercept = 5/2

y = mx + b (m is your slope and b is your y int)
y = -1/3x + 5/2
Do you understand ?

Answer 34

ohh i get it

Answer 35

good to hear :)

Answer 36

another one?

Answer 37

It is not really that hard...you just need to learn the formulas. Yes..I can help with another one

Answer 38

What is the equation of the line that passes through the points (1, 2/3) and (-1,-1)?

Answer 39

do i need to use this formula y = mx + b?

Answer 40

find the slope
slope(m) = (y2 - y1) / (x2 - x1)
(1,2/3) x1 = 1 and y1 = 2/3
(-1,-1) x2 = -1 and y2 = -1
time to sub
slope(m) = (-1-2/3) / (-1-1)
slope(m) = (-3/3 - 2/3) / (-2)
slope(m) = (-5/3) / -2
slope(m) = -5/3 * - 1/2
slope(m) = 5/6

this was a little tricky because of the fraction. Look over this and see if you have any questions....then we will move one to finding the equation

Answer 41

typo....then we will move on to finding the equation

Answer 42

y=5/6x-1/6

Answer 43

right?

Answer 44

lets see..
y = mx + b
slope(m) = 5/6
use wither of your sets of points
(-1,-1) x = -1 and y = -1
now we sub
y = mx + b
-1 = 5/6(-1) + b
-1 = -5/6 + b
-1 + 5/6 = b
-6/6 + 5/6 = b
-1/6 = b
your equation is : y = 5/6x - 1/6
you got it :)

Answer 45

thanks so much

Answer 46

im done thanks

Answer 47

no problem...glad I could help