14.5E: Exercises
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- Aug 24, 2020
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Practice Makes Perfect
Exercise 14.5E.19 Use Pascal's Triangle to Expand a Binomial
In the following exercises, expand each binomial using Pascal’s Triangle.
- (x+y)4
- (a+b)8
- (m+n)10
- (p+q)9
- (x−y)5
- (a−b)6
- (x+4)4
- (x+5)3
- (y+2)5
- (y+1)7
- (z−3)5
- (z−2)6
- (4x−1)3
- (3x−1)5
- (3x−4)4
- (3x−5)3
- (2x+3y)3
- (3x+5y)3
- Answer
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2. a8+8a7b+28a6b2+56a5b3+70a4b4+56a3b5+28a2b6+8ab7+b8
4. p9+9p8q+36p7q2+84p6q3+126p5q4+126p4q5+84p3q6+36p2q7+9pq8+q9
6. a6−6a5b+15a4b2−20a3b3+15a2b4−6ab5+b6
8. x3+15x2+75x+125
10. y7+7y6+21y5+35y4+35y3+21y2+7y+1
12. z6−12z5+60z4−160z3+240z2−192z+64
14. 243x5−405x4+270x3−90x2+15x−1
16. 27x3−135x2+225x−125
18. 27x3+135x2y+225xy2+125y3
Exercise 14.5E.20 Evaluate a Binomial Coefficient
-
- (81)
- (1010)
- (60)
- (93)
-
- (71)
- (44)
- (30)
- (53)
-
- (31)
- (99)
- (70)
- (53)
-
- (41)
- (55)
- (80)
- (119)
- Answer
-
2.
- 7
- 1
- 1
- 45
4.
- 4
- 1
- 1
- 55
Exercise 14.5E.21 Use the Binomial Theorem to Expand a Binomial
In the following exercises, expand each binomial.
- (x+y)3
- (m+n)5
- (a+b)6
- (s+t)7
- (x−2)4
- (y−3)4
- (p−1)5
- (q−4)3
- (3x−y)5
- (5x−2y)4
- (2x+5y)4
- (3x+4y)5
- Answer
-
2. m5+5m4n+10m3n2+10m2n3+5mn4+n5
4. s7+7s6t+21s5t2+35s4t3+35s3t4+21s2t5+7st6+t7
6. y4−12y3+54y2−108y+81
8. q3−12q2+48q−64
10. 625x4−1000x3y+600x2y2−160xy3+16y4
12. 243x5+1620x4y+4320x3y2+5760x2y3+3840xy4+1024y5
Exercise 14.5E.22 Use the Binomial Theorem to Expand a Binomial
In the following exercises, find the indicated term in the expansion of the binomial.
- Sixth term of (x+y)10
- Fifth term of (a+b)9
- Fourth term of (x−y)8
- Seventh term of (x−y)11
- Answer
-
2. 126a5b4
4. 462x5y6
Exercise 14.5E.23 Use the Binomial Theorem to Expand a Binomial
In the following exercises, find the coefficient of the indicated term in the expansion of the binomial.
- y3 term of (y+5)4
- x6 term of (x+2)8
- x5 term of (x−4)6
- x7 term of (x−3)9
- a4b2 term of (2a+b)6
- p5q4 term of (3p+q)9
- Answer
-
2. 112
4. 324
6. 30,618
Exercise 14.5E.24 Writing Exercises
- In your own words explain how to find the rows of the Pascal's Triangle. Write the first five rows of Pascal's Triangle.
- In your own words, explain the pattern of exponents for each variable in the expansion of.
- In your own words, explain the difference between (a+b)n and (a−b)n.
- In your own words, explain how to find a specific term in the expansion of a binomial without expanding the whole thing. Use an example to help explain.
- Answer
-
2. Answers will vary
4. Answers will vary
Self Check
a. After completing the exercises, use this checklist to evaluate your mastery of the objectives of this section.

b. On a scale of 1-10, how would you rate your mastery of this section in light of your responses on the checklist? How can you improve this?