Math 10C
Polynomials: Lesson #4
Multiplying Polynomials
Objective: By the end of this lesson, you will be able to:
- Multiply any two polynomials
- Combine polynomial operations of multiplying, adding, and subtracting
We can combine the operations of addition, subtraction, and multiplication on polynomials. To
do this, remember to use Order of Operations: ___________________.
Remember: You can only add and subtract __________ __________.
e.g. 1) Expand and simplify  y  24 y  1  2 y  3 .
2
e.g. 2) Find the product of 3a5a  2ba  2b .
We can generalize the rule for multiplying two binomials to multiply polynomials with more
terms.


e.g. 3) Expand and simplify x  7 2 x 2  3x  2 .
Math 10C
Polynomials: Lesson #4




e.g. 4) Explain the difference between x  7 2 x 2  3x  2 and x  7 2 x 2  3x  2 .



e.g. 5) Expand and simplify n 2  5n  1 4n 2  2n  5 .
e.g. 6) Find the error in this multiplication: 25 x  1
2
 10 x  2
 10 x  210 x  2
2
 100 x 2  40 x  4
2
Then correctly expand and simplify 25 x  1 .
Math 10C
Polynomials: Lesson #4
e.g. 6) a) Write and simplify an expression for the area of the figure shown.
x 1
2x
2x
3x  6
x 1
x 2  x  10
b) Find the area if x  5 ft.
Assignment: Polynomials Assignment #6f-8
Extra Practice: p. 186-187 #5, 8-10, 13, 15-17, 19