# Pre-Algebra Examples

,

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

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).

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

Simplify.

Simplify the numerator.

Multiply by .

Subtract from .

Simplify the denominator.

Multiply by .

Subtract from .

Move the negative in front of the fraction.

Use the slope and one of the given points such as to substitute for and in the point-slope form , which is derived from the slope equation .

After finding the slope between the points, use point-slope form to set up the equation. Point-slope is derived from the equation for slope .

Multiply by .

Simplify .

Simplify the expression.

Multiply by .

Apply the distributive property.

Simplify .

Write as a fraction with denominator .

Multiply and .

Simplify .

Multiply by .

Write as a fraction with denominator .

Multiply and .

Multiply by .

Simplify each term.

Move to the left of the expression .

Multiply by .

Move all terms not containing to the right side of the equation.

Add to both sides of the equation.

Simplify the right side of the equation.

To write as a fraction with a common denominator, multiply by .

Write each expression with a common denominator of , by multiplying each by an appropriate factor of .

Combine.

Multiply by .

Combine the numerators over the common denominator.

Simplify the numerator.

Multiply by .

Add and .

The final answer is the equation in slope-intercept form.