# Precalculus Examples

,

Step 1

Slope is equal to the change in over the change in , or rise over run.

Step 2

The change in is equal to the difference in x-coordinates (also called run), and the change in is equal to the difference in y-coordinates (also called rise).

Step 3

Substitute in the values of and into the equation to find the slope.

Step 4

Step 4.1

Simplify the numerator.

Step 4.1.1

Multiply by .

Step 4.1.2

Add and .

Step 4.2

Simplify the denominator.

Step 4.2.1

Multiply by .

Step 4.2.2

Add and .

Step 4.3

Dividing two negative values results in a positive value.

Step 5

The slope of a perpendicular line is the negative reciprocal of the slope of the line that passes through the two given points.

Step 6

Step 6.1

Multiply the numerator by the reciprocal of the denominator.

Step 6.2

Multiply .

Step 6.2.1

Multiply by .

Step 6.2.2

Multiply by .

Step 7