Question

Someone please help me i am so bad with point slope stuff

Write the equation of the line that passes through the points (2,−6) and (6,-6).
Write the equation of the line that passes through the points (9,8)and (6,3).
Write the equation of the line that passes through the points (-9,-4) and (-9,-4).
What is the equation of the line that passes through the point (−8,5) and has a slope of 0?
What is the slope of the line that passes through the points (-2, 7)and (2, -5).
What is the slope of the line that passes through the points (6, -5)and (6, -8).

Answer 1

1.) y = -6

2.) y = 5/3x - 7

3.) y = 5

4.) y = -3x + 1

5.) x = -3

Explanation:

So the equation you want to use is this:
`(y2-y1)/(x2-x1)`

1.) Plug in

`(-6 - (-6))/(6 - 2) \\\\(0)/(4) = 0\\`

This line is zero slope to find the y-intercept get one of you points and plug them and the slope into this equation y = mx+ b. We will use (2,-6)

-6 = 0(2) + b (b represents y-intercept) (0*2=0)

-6 = b

So the equation is y = -6

2.) Do the same thing.

`(3-8)/(6-9) \\\\(-5)/(-3) =(5)/(3)`

It's positive because when you divide a negative by a negative you get a positive. Plug in a point (6, 3) y = mx + b (b represents y-intercept)

3 = 5/3(6) + b (5/3*6 = 10)

3 = 10 + b (subtract 10 on both sides)

-7 = b

y = 5/3x - 7

3.) For this one you are just going to point slope form. y - y1 = m(x - x1)

Plug in

y - 5 = 0(x - (-8))

y - 5 = 0 (add 5 to both sides)

y = 5

4.) Do
`(y2 - y1)/(x2 - x1)` for this one

Plug in

`(-5 - 7)/(2 - (-2)) \\\\(-12)/(4) = -3`

So the slope is -3. Plug into y = mx + b with the point (2, -5)

-5 = -3(2) + b (b represents y-intercept)

-5 = -6 + b (add 6 to both sides)

1 = b

The equation is y = -3x + 1

5.) Do the same thing as #4

`(-8 - (-5))/(6 - 6) \\\\(-3)/(0)`

This slope is undefined

Since you can't divide by 0 the equation would be

x = -3

Hope this helps ya!!