FOIL

Use the FOIL technique to multiply monomials. Multiplying monomials is like multiplying 2 mx+b expressions together.

FOIL = First Outside Inside Last

Example: (x+3)(x+5)

First:          x \cdot x =x^2
Outside:     x \cdot 5 = 5x
Inside:       3 \cdot x = 3x
Last:          3 \cdot 5 = 15

(x+3)(x+5)=x^2+5x+3x+15

Combine like terms…

=x^2+8x+15