Special Products and Factoring

Special Products
1.   $(x + y)(x - y) = x^2 - y^2$

2.   $(x + y)^2 = x^2 + 2xy + y^2$

3.   $(x - y)^2 = x^2 - 2xy + y^2$

4.   $(x + y)^3 = x^3 + 3x^2y + 3xy^2 + y^3$

5.   $(x - y)^3 = x^3 - 3x^2y + 3xy^2 - y^3$

6.   $(x + a)(x + b) = x^2 + (a + b)x + ab$

7.   $(ax + by)(cx + dy) = acx^2 + (ad + bc)xy + bdy^2$
 

Factoring Polynomials
1.   $ax + ay + az = a(x + y + z)$

2.   $x^2 - y^2 = (x + y)(x - y)$

3.   $x^3 + y^3 = (x + y)(x^2 - xy + y^2)$

4.   $x^3 - y^3 = (x - y)(x^2 + xy + y^2)$

5.   $x^2 + 2xy + y^2 = (x + y)^2$

6.   $x^2 - 2xy + y^2 = (x - y)^2$

7.   $x^2 + (a + b)x + ab = (x + a)(x + b)$

8.   $acx^2 + (ad + bc)xy + bdy^2 = (ax + by)(cx + dy)$