Multiplying Polynomials 95
Solution
a. ()^53 y )()(^26 y
Step 1. Multiply the numerical coeffi cients.
()^5 ()^3 =^15
Step 2. Multiply the variable factors.
()xy^53 ()xy^26 =x^7 y^9
Step 3. Use the product in step 1 as the coeffi cient
of xy^79.
()^5 xy^53 ()^3 xy^26 =^15 xy^79
b. ()^343 )()( b^2
Step 1. Multiply the numerical coeffi cients.
()− )()( =−^16
Step 2. Multiply the variable factors.
()ab^34 b ()ab^2 =ab^46
Step 3. Use the product in step 1 as the coeffi cient of ab^46 b.
()− )()( )=−^1616 ab^446
c.())))()(((
Step 1. Multiply the numerical coeffi cients.
())()( )=− 12
Step 2. Multiply the variable factors.
()x()x =x^2
Step 3. Use the product in step 1 as the coeffi cient of x^2.
() 6 x() 22 x =− 12 x^2
d. ()^32 )))()(((
Step 1. Multiply the numerical coeffi cients.
() 10 )(() 44 ))=− 0
To streamline your work when
you are multiplying polynomials,
arrange the variables in each term
alphabetically.
Recall from Chapter 7 that
when you multiply exponential
expressions that have the same
base, you add the exponents.
If no exponent is written on
a variable, the exponent is
understood to be 1.