Question

Help please: attached

Answer 1

y-y1=m(x-x1)
this is point slope form
you need to know a point (x1,y1) and the slope m=(y2-y1)/(x2-x1), you need to know 2 points of the line for the slope, (x1,y1) and (x2,y2)

Answer 2

Point slope:
\[y - y_1 = m(x-x_1)\]
Slope Intercept form:
y = mx + b

Answer 3

You are already given the slope and a point. Now just plug in the values for m, y1 and x1.

Answer 4

-5-y=-1/4(-6-x)

Answer 5

No, you plug in -5 for y1 and -6 for x1

Answer 6

y+5=-1/4(x+6)

Answer 7

Yes, now distribute -1/4

Answer 8

y+5=-1/4x-1.5

Answer 9

y=-1/4x-6.5

Answer 10

Ivonne, this problem is very, very similar to the one we did 40 minutes ago.
The illustration gives you the slope of the line (m=-1/4) and one point (-6,-5) on that line. You are required to start with the point-slope form of the equation of a line (similar to last time).

That point-slope form is y-k=m(x-h).

Since the point is (-6,-5), h=-6 and k=-5; the slope is m=-1/4.

Just substitute.

Might be a good idea to take a few notes on each problem solution, to help you remember when you have to apply the same knowledge or methods to a new situation.

Answer 11

Thats it.

Answer 12

You end up with slope-intercept form, as required, after having started with the point-slope form.

Answer 13

@mathmale would this be the correct form?

Answer 14

You have arrived at y = -x/4 + 13/2, and want to know whether or not this is the correct form. To check this equation, go back and fetch the given point; it is (-6,-5).

Substitute -5 for y in the above equation, and -5 for x.

-5=-(-6)/4 + 13/2. You want to know whether this is true or not.

Multiplying every term by 4 eliminates the fraction 1/4:

-20=6+26

Does -20=32? Obviously not, so something is wrong here.

Answer 15

Ok

Answer 16

Look back to what we did earlier. YOU found that y+5=-1/4(x+6)

Let's mult. both terms (there are only 2 terms at the moment) by -4 to eliminate the fraction (-1/4):

-4y - 20 = x + 6.

You must solve this for y to obtain an equation in slope-intercept form.

Divide all terms by -4 now.

y=??

Answer 17

-4y=x+26

Answer 18

y=x/-4 - 6

Answer 19

\[y=-\frac{ 1x }{ 4 }- 6\]

Answer 20

As before, you need to check your answer. To do this, determine whether or not the given point (-6,-5) satisfies YOUR latest equation.
If it does, your answer is correct; otherwise your answer is not correct.

Substitute -5 for y now, followed by subst. -6 for x.

Is the resulting equation true?

Answer 21

i believe not

Answer 22

why

Answer 23

We will have to find out what went wrong as you went from one form (point-slope) to another form (slope-intercept).

What was your very first answer (point-slope form)?

Answer 24

I dont know

Answer 25

I was asking you to go back and locate your own work.

What I'm going to do now is to forget about the point-slope form and jump directly into slope-intercept form.

Look at the given graph. The line goes thru which point? The line has what slope?:

Answer 26

-1/4

Answer 27

yes, and that line goes thru which given point?

Answer 28

given : (-6, -5)

Answer 29

Yes. Now we'll jump directly to slope-intercept form: y=mx+b. We know all of y, m and x, but don't know b yet.

subst. -5 for y, -6 for x, and (-1/4) for m.

Find b.

Answer 30

Reviewing your past work, it seems as tho you had the correct answer, except for the sign of 13/2.

Almost finished with your latest calculations?

Answer 31

-13/2

Answer 32

Right. Slope is -1/4, y-intercept is -13/2.

Equation is then y = (-1/4)x - 13/2. That's it.

Answer 33

would it be ok to put: \[y=-\frac{ 1x }{ 4 } - \frac{ 13 }{ 2 }\]

Answer 34

Yes. That's correct. But I still think you should check it once more. Does this line pass thru (-6,-5)?

To check that, let x=-6 in your equation (above). Does the equation predict that =-5?

Answer 35

yes just double checked it

Answer 36

Then you have the correct equation. The only thing wrong with your previos result was that your sign for 13/2 was incorrect.

Answer 37

Thank you for the medal!