1. Factor out the common factors.
2. If there’s an expression with two terms, try to identify it as one of these problem types, if possible:
a. Difference of two squares: .
b. Sum of two cubes: .
c. Difference of two cubes: .
3. If an expression has four or more terms, try to factor it by grouping.
4. Factor the expression until each factor is prime, and check your final results by multiplying.