Identifying Special Situations in Factoring

Difference of two squares

-a²- b² = (a + b)(a - b)

Trinomial perfect squares

--a² + 2ab + b²= (a + b)(a + b) or (a + b)²

^{--a2 - 2ab + b2 = (a - b)(a - b) or (a - b)2}

Difference of two cubes

--a³ - b³

3 - cube root 'em

2 - square 'em

1 - multiply and change

Sum of two cubes

--a³ + b³ 

3 - cube root 'em

2 - square 'em

1 - multiply and change

Binomial expansion

--(a + b)³ 

--(a + b)⁴