Help needed for point slope form

Question

Hello, it says I need to find the point slope form of points 18, 4 and -11, 1. With the same points I need to find slope intercept form.

I also need to find the point slope form of 1, 11 with the slope -4/5. With this, I also need to find the slope intercept form. Please help

Answer 1

I will work the first one for you, then you apply the same reasoning to the second one.

Points (18,4) and (-11,1)

m = (4 - 1)/[18 - (-11)] = 3/29

The point slope form of the equation is

y - y₁ = m(x - x₁)

Plug in

m = 3/29

x₁ = 18

y₁ = 4

or

x₁ = -11

y₁ = 1

Either point will give a correct equation. Using (18,4),

y - 4 = (3/29)(x - 18)

To get the point intercept form, you want

y = mx + b

Using the same point,

4 = (3/29)(18) + b

Solve for b, plug your answer for and m=3/29 into

y = mx + b