Question

attachment below. please help!

Answer 1

For part a, Use the point slope formula. Start by finding the slope between the two points, and then using one of the points to complete the equation.
For b, use the slope intercept form. You just have to plug in the given values.
For c. use the standard form.

Answer 2

its like y - 1 over something

Answer 3

Google them.

Answer 4

y-intercept formula: y=mx+b
point slope formula: y-y1=m(x-x1)
standard form: ax+by=c

Answer 5

For part A, do you know how to find the slope between 2 points?

Answer 6

nope, I honestly haven't done this in a while.

Answer 7

Look at this video. It should explain how to find the slope between 2 points: http://www.youtube.com/watch?v=S3-rW69H3Ro

Answer 8

The thing is, I can do the work for you, but you sometimes have to learn how to do it yourself.

Answer 9

can someone give me an example and steps? thats the only way I can do it/

Answer 10

http://www.algebra.com/algebra/homework/Graphs/Slope-of-a-Line-between-two-points.lesson
http://www.algebralab.org/lessons/lesson.aspx?file=geometry_coordslope.xml

Answer 11

Once you find the slope, you can confirm it with what i've got.

Answer 12

I get it! ok can you help me on the first two steps on the first task then I can take it from there.

Answer 13

All I have a problem with doing is putting in the numbers.

Answer 14

hmm

Answer 15

For part a, what did you get for the slope?

Answer 16

For part a:
-find the slope of the line between the two points:

m = (y2 - y1) / (x2 - x1)

then find the y intercept:

y = mx + b
therefore, b = y - mx

solve for b

y = mx + b (replace m and b with what you calculate)
(This is your slope-intercept form)

Answer 17

when you solve for b you pick either of the points and substitute their x and y values in

Answer 18

what numbers do you put in for it? I'm sorry I'm really bad at this. Is it 1/2?

Answer 19

Here goes:

usually we find the slope first:

our points are (-1,4) and (-5, 2)

m = (2 - 4)/(-5 - (-1)

since subtracting a negative is the same as adding a positive:
m = (2 - 4)/(-5 + 1)

do addition and subtraction first according to BEDMAS/PEDMAS:
m = -2/-4

divide the numerator and denominator by 2:
m = 1/2

Answer 20

next,

for the b value(y-intercept):

I use b = y - mx

(This comes from taking y = mx + b and subtracting mx from each side)

so b = y - (1/2)x

Answer 21

we can use either point but I'll pick (-1, 4) randomly.

Now put x and y from this point into the equation:

b = y - (1/2)x
b = 4 - (1/2)(-1)

Answer 22

since you were subtracting a negative:

b = 4 - (1/2)(-1)
is the same as:
b = 4 + (1/2)

to do addition with fractions you need the same denominators:
b = 8/2 + 1/2
b = 9/2

Answer 23

OMG thank you so much! I get it. Alright so all of those are the steps to lead up to 9/2? (just checking)

Answer 24

yeap

Answer 25

so what is the equation you make from the m and b values?

Answer 26

wait, wait, wait. equation?

Answer 27

maybe I don't get it..haha

Answer 28

I am confused. What should I put down for the steps? like what is m and what is b?

Answer 29

-1,4 is m?

Answer 30

-5,2 is b?

Answer 31

the question wants you to find the equation that goes through those two points.

we found m to be 1/2 and b to be 9/2 so we fill in the slope-intercept equation:

y = mx + b

y = (1/2)x + (9/2) <--- this is an equation of a line.

But we need to find this equation in two other forms.

Answer 32

The steps depend on what you're given:

Given two points:

1] find m (Using m = (y2 - y1)/(x2 - x1) )

2] find b(Using b = y-mx)
(You'll need to put m and the x and y from one point into this equation)(Doesn't matter which point you choose)

3] make the equation: y = mx + b
(Leave x and y as letters and replace m and b with what you found in step 1 and 2)

Answer 33

ok these are the steps right?

Answer 34

I'm just confused what's what.

Answer 35

those are the steps

Answer 36

see if this helps you:
http://www.purplemath.com/modules/strtlneq.htm

Answer 37

most of all, practice! :)

Answer 38

gotta go, good luck

Answer 39

ok thank you! and you did a few steps D:

Answer 40

what should I write down?

Answer 41

@ChmE

Answer 42

slope-intercept form:\[y=mx+b\]m is the slope, b is the y-intercept. You use this formula when you have the slope and intercept.\[y-y_1=m(x-x_1)\]where m is the slope and you have a point (x1, y1). You use this formula when you have a point and the slope.

Now I'll talk about each part

Answer 43

ok, wait.. so this is a? can you do it by step like, step 1, step 2

Answer 44

a) we are given 2 points. The first step will be to find the slope. the slope formula is \[m=\frac{ y_2-y_1 }{ x_2-x_1 }\]Now that we have the slope the fastest way to arrive at an equation is to use point slope form, since we only have a point and the slope.

Answer 45

this is step one?

Answer 46

\[\frac{ 2-4 }{ -5-(-1) }=\frac{ -2 }{ -4 }={1 \over 2}=m\]\[y-y_1={1 \over 2}(x-x_1)\]\[y-4={1 \over 2}(x-(-1))\]You need to solve this for y and that will be the equation of the line.

Answer 47

what's step one? O_O

Answer 48

Step 2) would be to plug in the information into point-slope form and get the equation of the line

Answer 49

Are you understanding this so far? Do you have any questions?

Answer 50

oh! yeah now I get what you're saying, haha ok so second step?

Answer 51

I already posted it

Answer 52

third I meant, I'm sorry

Answer 53

part a) is done

Answer 54

b) We are given the slope and y-intercept. We can simply plug these values into the slope-intercept formula to get the equation of the line. \[y=mx+b\]\[y=2x-4\]Part b is done

Answer 55

wait what's the answer for a? I'm still getting a bit confused like what's what.

Answer 56

c) we have the x intercept and y intercept. This tells us 2 things. x-intercept is when y=0 so we have the point (6,0). The y-intercept is when x=0 so we have the point (0,3). Step 1 is to find the slope.\[m=\frac{ 3-0 }{ 0-6 }=\frac{ 3 }{ -6 }=-\frac{ 1 }{ 2 }\]We will use the slope-intercept formula for this part because now we have slope and y-intercept so we just plug these values in.\[y=-{1 \over 2}x+3\]Part c is done

Answer 57

I understand b and c. I don't understand a.

Answer 58

y=2x-4 and y=-1/2x+3 is the answer for b and c? right?

Answer 59

Part d) we are given a point and a slope. If you recall what I said earlier, if you have these two things we will use point-slope form. \[y-2=-{5 \over 3}(x-1)\]

Answer 60

yes those are the answers to b and c

Answer 61

An easy trick to remembering what formula to use is to just look at the name. slope-intercept formula you use when you have the slope and y-intercept. point-slope formula you use when you have a point and a slope

Answer 62

part a) you need to get rewrite the equation so that y is by itself. That will be the final answer

Answer 63

\[y-4={1 \over 2}(x-(-1))\]\[y-4={1 \over 2}(x+1)\]\[y-4={1 \over 2}x+{1 \over 2}\]\[y-4+4={1 \over 2}x+{1 \over 2}+4\]\[y={1 \over 2}x+{1 \over 2}+{8 \over 2}\]\[y={1 \over 2}x+{9 \over 2}\]^ final answer ^

Answer 64

Now you do the same for part d)

Answer 65

alright..I understand a now but what's d? what am I figuring out?

Answer 66

like not the answer but steps

Answer 67

I posted it above. It's only one step. You need to solve the equation like I did for a