What Does FOIL Stand For?
The standard mnemonic for multiplying two binomials:
FIRST (F)
First Terms
Multiply first terms of each binomial: (ax) · (cx) = acx².
OUTER (O)
Outer Terms
Multiply outer terms on the ends: (ax) · (d) = adx.
INNER (I)
Inner Terms
Multiply inner middle terms: (b) · (cx) = bcx.
LAST (L)
Last Terms
Multiply last constant terms: (b) · (d) = bd.