Multiplying Binomials - Central/Southern Tier RAEN

Name: ___________________________
Multiplying Binomials
Date: ________________
Many teachers like to use FOIL (First, Outer, Inner, Last) to teach multiplying binomials, but we find this method
can be confusing and really only works when you are multiplying two binomials. What happens when you have
to multiply three or more?
Instead of FOIL, we use a Punnett Square and this method also engenders some crossover between math and
science!
Example #1: (π‘₯ + 6)(π‘₯ + 3)
x
+6
π‘₯2
+6π‘₯
+3π‘₯
+18
x
+3
Thus, π‘₯ 2 + 6π‘₯ + 3π‘₯ + 18
π’™πŸ + πŸ—π’™ + πŸπŸ–
When multiplying three (or more) binomials, multiply two binomials at a time.
Example #2: (π‘₯ + 5)(π‘₯ βˆ’ 3)(π‘₯ + 2)
π‘₯
+5
π‘₯2
+5π‘₯
βˆ’3π‘₯
βˆ’15
π‘₯
βˆ’3
Thus, π‘₯ 2 + 5π‘₯ βˆ’ 3π‘₯ βˆ’ 15
π‘₯ 2 + 2π‘₯ βˆ’ 15
Next, take the resulting trinomial and multiply it by the remaining binomial.
π‘₯2
π‘₯
+2
Kopp & Rossi²
+2π‘₯
βˆ’15
π‘₯3
+2π‘₯ 2
βˆ’15π‘₯
+2π‘₯ 2
+4π‘₯
βˆ’30
Thus, π‘₯ 3 + 2π‘₯ 2 βˆ’ 15π‘₯ + 2π‘₯ 2 + 4π‘₯ βˆ’ 30
π’™πŸ‘ + πŸ’π’™πŸ βˆ’ πŸπŸπ’™ βˆ’ πŸ‘πŸŽ
1
Multiplying Three Binomials
Simplify each expression.
1. (t + 3)(t + 2)(t + 5)
2. (z βˆ’ 2)(z βˆ’ 5)(z + 2)
3. (d βˆ’ 4)(d + 2)(d βˆ’ 3)
4. (y βˆ’ 2)(y βˆ’ 1)(y + 3)
5. (c + 6)(c βˆ’ 4)(c + 2)
Kopp & Rossi²
2
Multiplying Three Binomials
Simplify each expression.
6. (t + 4)(t + 2)(t βˆ’ 1)
7. (z βˆ’ 4)(z βˆ’ 3)(z + 2)
8. (d βˆ’ 9)(d + 1)(d βˆ’ 4)
9. (y + 2)(y βˆ’ 2)(y + 2)
10. (c + 6)(c βˆ’ 3)(c + 1)
Kopp & Rossi²
3
Multiplying Three Binomials
Simplify each expression.
11. (t βˆ’ 3)(t + 6)(t βˆ’ 5)
12.
(z βˆ’ 1)(z βˆ’ 6)(z + 2)
13.
(d βˆ’ 2)(d + 2)(d βˆ’ 3)
14.
(y βˆ’ 4)(y βˆ’ 4)(y + 3)
15.
(c βˆ’ 6)(c βˆ’ 6)(c βˆ’ 6)
Kopp & Rossi²
4
Multiplying Three Binomials
Simplify each expression.
16. (t + 4)(2t + 2)(2t βˆ’ 1)
17. (z βˆ’ 4)(z βˆ’ 3)(2z + 2)
18. (2d βˆ’ 4)(2d + 1)(d βˆ’ 4)
19. (3y + 2)(y βˆ’ 2)(2y + 2)
20. (βˆ’3c + 6)(c βˆ’ 3)(2c + 1)
Kopp & Rossi²
5
Name: ___________________________
Multiplying Binomials
Date: ________________
1). Which of these is equivalent to (π‘₯ βˆ’ 3)2 ?
A. π‘₯ 2 βˆ’ 6π‘₯ + 9
B. π‘₯ 2 + 6π‘₯ + 9
C. π‘₯ 2 βˆ’ 3
D. π‘₯ 2 + 3
2). Which of these is equivalent to (π‘₯ βˆ’ 2)2 ?
F. π‘₯ 2 + 4
G. π‘₯ 2 βˆ’ 4
H. π‘₯ 2 + 4π‘₯ + 4
J. π‘₯ 2 βˆ’ 4π‘₯ + 4
3). Which of these is equivalent to (π‘₯ + 5)2 ?
A. π‘₯ 2 + 10π‘₯ βˆ’ 25
B. π‘₯ 2 + 10π‘₯ + 25
C. π‘₯ 2 βˆ’ 5
D. π‘₯ 2 + 5
4). What is (π‘₯ + 9)(π‘₯ + 4)(π‘₯ + 2)?
F. π‘₯ 3 βˆ’ 15π‘₯ 2 βˆ’ 62π‘₯ βˆ’ 72
G. π‘₯ 3 + 15π‘₯ 2 + 62π‘₯ βˆ’ 72
H. π‘₯ 3 + 15π‘₯ 2 + 62π‘₯ + 72
J. π‘₯ 3 + 15π‘₯ + 62π‘₯ + 72
5). What is (π‘₯ + 2)(π‘₯ βˆ’ 1)(π‘₯ + 3)?
A. π‘₯ 3 + 4π‘₯ 2 + π‘₯ + 6
B. π‘₯ 3 + 4π‘₯ 2 + π‘₯ βˆ’ 6
C. π‘₯ 3 βˆ’ 4π‘₯ 2 βˆ’ π‘₯ + 6
D. π‘₯ 3 βˆ’ 4π‘₯ 2 βˆ’ π‘₯ βˆ’ 6
6). What is the coefficient of the term with the highest degree in the polynomial expression
13π‘₯ βˆ’ 6π‘₯ 2 βˆ’ 7π‘₯ 4 + 5π‘₯ 3 + 12?
F. βˆ’6
G. βˆ’7
H. 13
J. 5
7). What is the coefficient of the term with the highest degree in the polynomial expression
βˆ’4π‘₯ 2 + 6π‘₯ βˆ’ 3π‘₯ 3 + 2π‘₯ 4 βˆ’ 23?
A. βˆ’4
B. 2
C. βˆ’3
D. βˆ’23
Kopp & Rossi²
Name: ___________________________
Multiplying Binomials
Date: ________________
8). A developer makes a blueprint using the rectangle shown below. (𝐴 = 𝑙𝑀)
(π‘₯ + 3)
(π‘₯ βˆ’ 3)
What is an equivalent expression for the area of this rectangle?
F. π‘₯ 2 βˆ’ 9
G. π‘₯ 2 βˆ’ 3π‘₯
H. π‘₯ 2 βˆ’ 6π‘₯ βˆ’ 9
J. π‘₯ 2 + 6π‘₯ βˆ’ 9
1
9). A developer makes a blueprint using the triangle shown below. (𝐴 = 2 π‘β„Ž)
(π‘₯ βˆ’ 5)
5π‘₯
What is an equivalent expression for the area of this triangle?
1
A. 2 π‘₯ 2 + 5
B. 5π‘₯ 2 βˆ’ 25π‘₯
C.
D.
π‘₯ 2 βˆ’5
2
5π‘₯ 2 βˆ’25π‘₯
2
10). What is the volume of the cube?
(π‘₯ + 3)
F. π‘₯ 3 βˆ’ 2π‘₯ 2 βˆ’ 11π‘₯ βˆ’ 12
G. π‘₯ 3 + 2π‘₯ 2 + 11π‘₯ + 12
H. π‘₯ 3 βˆ’ 2π‘₯ 2 βˆ’ 11π‘₯ + 12
J. π‘₯ 3 βˆ’ 2π‘₯ 2 βˆ’ 11π‘₯ βˆ’ 12
Kopp & Rossi²
(π‘₯ βˆ’ 1)
(π‘₯ βˆ’ 4)
Name: ___________________________
ANSWER KEY
1) A
2) J
3) B
4) H
5) B
6) G
7) B
8) F
9) D
10) H
Kopp & Rossi²
Multiplying Binomials
Date: ________________