# 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 to get .

Subtract from to get .

Simplify the denominator.

Remove parentheses.

Multiply by to get .

Add and to get .

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 to get .

Simplify the right side.

Simplify the expression.

Multiply by to get .

Apply the distributive property.

Simplify .

Write as a fraction with denominator .

Multiply and to get .

Simplify .

Multiply by to get .

Write as a fraction with denominator .

Multiply and to get .

Multiply by to get .

Simplify each term.

Move to the left of the expression .

Multiply by to get .

Move the negative in front of the fraction.

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

Since does not contain the variable to solve for, move it to the right side of the equation by adding to both sides.

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 to get .

Combine the numerators over the common denominator.

Multiply by to get .

Multiply by to get .

Subtract from to get .

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