Foil Formula

FOIL is a mnemonic for the standard method of multiplying two binomials, hence the method may be referred to as the FOIL method.

foil

The word FOIL is an acronym for the four terms of the product:

  • First (“first” terms of each binomial are multiplied together)
  • Outer (“outside” terms are multiplied—that is, the first term of the first binomial and the second term of the second)
  • Inner (“inside” terms are multiplied—second term of the first binomial and first term of the second)
  • Last (“last” terms of each binomial are multiplied)

The general form is:

fpil 2

Solved Examples

Question 1: Evaluate (2x+4)(5x+3) ?

Solution:

Given function is, (2x + 4) (5x + 3)

According to foil formula,

$(2x + 4) (5x + 3) = (2x \times 5x + 2x \times 3) + (4 \times 5x + 4 \times 3)$
$(2x + 4) (5x + 3) = 10x^{2} + 6x + 20x + 12$
$(2x + 4) (5x + 3) = 10x^{2} + 26x + 12$


Practise This Question

Stability of the species Li2, Li2 and Li2+ increases in the order of