Multiplying a Polynomial by a Monomial
To multiply a monomial by a polynomial with more than one term,
use the Distributive Property to distribute the monomial to each term
in the polynomial.
Example 1Find: -8w3y(4w2y5 - w4)
Solution |
|
-8w3y(4w2y5 - w4) |
Multiply each term in
the polynomial by the
monomial, -8w3y. |
|
= (-8w3y)(4w2y5) - (-8w3y)(w4) |
Within each term, write the coefficients next to each other. Write the
factors with base w next to each other and write the factors with base y
next to each other. |
|
= (-8 · 4)(w3
· w2)(y
· y5) - (-8)(w3
· w4)(y) |
Use the Multiplication
Property of Exponents. |
|
= (-8 · 4)(w3 + 2 y1
+ 5) - (-8)(w3 + 4 y) |
Simplify. |
|
= -32w5y6 + 8w7y |
Example 2
Find: 5x4(3x2y2 - 2xy2 + x3y)
Solution |
|
5x4(3x2y2 - 2xy2 + x3y)
|
Multiply each term in the polynomial by the monomial, 5x4.
|
|
= (5x4)(3x2y2) - (5x4)(2xy2)
+ (5x4)(x3y) |
Within each term, write the coefficients next to each other. Write the
factors with base x next to each other and write the factors with base y next
to each other. |
|
= (5 · 3)(x4
x 2 y2) - (5 ·
2)(x4 x 1y2) + (5
· 1)(x4 x 3 y)
|
Use the Multiplication Property of Exponents. |
|
= (5 · 3)(x4 + 2
y2) - (5 · 2)(x4
+ 1 y2) + (5 · 1)(x4
+ 3 y) |
Simplify. |
|
= 15x6y2
- 10x5y2 + 5x7y
|
|