Question

A-line includes the points (8,9) and (9,1). What is its equation in point-slope form?

Answer 1

`y-(9)=(-8)(x-8)\\`

Explanation:

`(x_1, y_1) = (8, 9)\\(x_2, y_2) = (9,1)\\`

Step one: Find the slope (m)

`slope=m=(rise)/(run) =(y_2-y_1)/(x_2-x_1) = (1-9)/(9-8) =(-8)/(1) =-8`

Step two: Plug your known values into the point-slope equation

`m=-8\\y_1=9\\x_1=8\\`

Point-slope form is
`y-y_1=m(x-x_1)`

`y-(9)=(-8)(x-8)\\`

If you want to convert point-slope form to general form, isolate for y.

`y-9=-8x+64\\y=-8x+73`