FOILWhat the heck is it

1
FOILWhat the heck is it?

• When we look at a pair of binomials that need to
  be multiplied together, how do we go about
  multiplying without forgetting anything?
• (x3)(x2)

2
We FOIL!

• FOIL is an acronym that stands for
• First
• Outside
• Inside
• Last
• This is the quick and easy way to remember how to
  multiply binomials.

3
So lets get started!

• The first part of our job is to multiply the
  First terms of each binomial together. So this
  means that in our example we multiply x and x
• (x3)(x2)
• And the answer is?
• x-squared

4
That was easy, lets continue!

• Now that we have our first product, we must
  multiply the Outside terms. The Outside terms
  include x (in the first binomial) and 2 (in the
  second binomial)
• (x3)(x2)
• And the answer is?
• 2x

5
Wow! Were on a roll!

• Now its time to multiply the Inner terms of each
  binomial. These are represented by 3 (in the
  first binomial) and x (in the second binomial)
• (x3)(x2)
• And the answer is?
• 3x

6
Okay, lets review

• So far, weve multiplied the First, Outer and
  Inner terms. Lets take a quick look at our
  answers so far.
• x-squared 2x3x
• Now weve got one more set of terms to multiply
  so lets get going!

7
Almost done!

• Now its time to take care of that Last pair of
  terms. The Last terms are represented by 3 (in
  the first binomial) and 2 (in the second
  binomial)
• (x3)(x2)
• And the answer is?
• 6

8
Time to combine like terms

• Now that weve completed our multiplication of
  the binomials, we can see some like terms in our
  answer. Lets take a moment to combine those
  terms for our final answer.
• x-squared 2x3x6
• And our final answer is?
• x-squared 5x6

9
Woo-Hoo! You did it!

• As you can see, the FOIL Method will work with
  any pair of binomials. Once you get the hang of
  it, you cant lose!
• Now try some problems on your own for practice.
• Once youre done with the practice problems begin
  with the homework problems on page 314 numbers
  1-30.
• GREAT JOB!

10
Practice problems for FOIL

• (x6)(x4) 7. (2x-4)(x5)
• (x9)(x-3) 8. (4x-5)(2x-3)
• (x-4)(x2) 9. (x-12)(4x3)
• (x-2)(x2) 10. (2x3)(2x-3)
• (x5)(x5) 11. (-x1)(x-1)
• (x-3)(x-2) 12. (9x-1)(9x1)