-[-5] what expression csn express this​

The first thing we must do for this case is to find the equation of the line for CD.

We have then:

Where,

Substituting values:

We choose an ordered pair:

Substituting values:

Rewriting:

Then, we look for the equation of the line perpendicular to CD.

We have an equation of the form:

As the lines are perpendicular:

Then, as the line passes through the point (-1, 6) then substituting, we can find the value of b:

Then, the equation of the line is:

b. y = -0.5x + 5.5