Foil Method

How do you multiply:
(x + 11)(x – 11)

Use the foil method:
(x + 11)(x - 11)
= x(x) + x(-11) + 11(x) + 11(-11)  {used foil method}
= x² - 11x + 11x - 121  {multiplied through}
= x² - 121  {combined like terms}

Ask Algebra House