# Precalculus Examples

Factor using the AC method.
Consider the form . Find a pair of integers whose product is and whose sum is . In this case, whose product is and whose sum is .
Write the factored form using these integers.
Factor using the AC method.
Consider the form . Find a pair of integers whose product is and whose sum is . In this case, whose product is and whose sum is .
Write the factored form using these integers.
Cancel the common factor of .
Cancel the common factor.
Rewrite the expression.
To find the holes in the graph, look at the denominator factors that were cancelled.
To find the coordinates of the holes, set each factor that was cancelled equal to , solve, and substitute back in to .
Set equal to .
Add to both sides of the equation.
Substitute for in and simplify.
Substitute for to find the coordinate of the hole.
Simplify.