1
MA 220, Lesson 3, Textbook Section 5.3
Multiplying Polynomials (part 1)
To multiply a polynomial by any monomial multiplier, use the distributive property.
Ex 1:
2
(4
2
3)(5 )
x
x
x
Ex 2:
2
3
2
4 (3
2
6
9)
x
x
x
x
Be cautious when multiplying by a monomial with a negative coefficient.
Be sure to
distribute the negative sign.
Ex 3:
3
4 (6
2
1)
x x
x
When multiplying two binomials, the distributive property could be used; as illustrated below.
2
2
(4
3)(2
4)
4 (2
4) 3(2
4)
8
16
6
12
8
10
12
x
x
x x
x
x
x
x
F
O
I
L
xx
However, as seen above; the word FOIL may be used to help students remember to multiply four
pairs.
F (first terms in each binomial are multiplied), O (outer terms in each binomial are
multiplied), I (inner terms in each binomial), and L (last terms in each).
There is a good picture
on page 320 of the textbook that
shows logically why FOIL works by illustrating the area of a
rectangle (Figure 5.3).
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 Spring '08
 Staff
 Algebra, Polynomials, The Distributive Property, Addition, Distributive Property, Coefficient, ex

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