Page 340 - Start Up Mathematics_7

Solve Mentally 5. (a) x + 2xy + y 2 (b) 3x + 4y 2
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True or False
(Terms) x 2 2xy y 2 3x 2 4y 2
1. False 2. False 3. True 4. False 5. True
Fill in the Blanks (Factors) x x 2 x y y y 3 x x 4 y y
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1. 2, 5 2. 3 3. negative 4. a = b 5. 3 (c) x y + 2xy + 4
6. 0 7. 8. 1, 10 9. 5 × 10 12
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Answer in One Word or a Line x y 2xy 4
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1. 10 2. 100 3. 4. a = 1, –1 5. a x x y y 2 x y
m – n
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7 2 2 2 2
Let’s Evaluate 6. (a) 2x , x (b) ab c, b ac
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1. 2,197 2. 5 3. (–3) < (–5) 4. –1,45,800 7. (a) xy , – 4x y, 8x , 2xy , –4xy 2
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5. 2 × 3 × 5 6. (a)   − 3   7 (b)   − 2   18 (b) 7ab , 7a, 8b, –a b , –3ab , 6ba
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 5   7  (c) 7pq , 3p q, –3pq , –6pq , –qp
7. –1 8. 1,92,000 km Exercise 6.2
Thinking Skills 1. (a) 8x (b) 7x + 6x – 8x (c) 6a – 3b + ab
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14 (d) 3x + x + 3y – 9
3 
1.    2. 4.06 × 10 miles
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 5  2. (a) ab (b) 4xy (c) 6x + 2y + 6xy + 8
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3. (a) 600 m (b) 1,600 m 2 (d) –5x y – 14xy 2
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4. The metals arranged in descending order of magnitudes. 3. (a) x + y + z (b) 11a (c) 2x + 2y + 2
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Copper; 8.96 × 10 > Chlorine; 2.95 × 10 > Oxygen; 4. (a) 11xy (b) –5x (c) 4ab (d) x – 4y + 4x y
–3
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2 2
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1.429 × 10 > Nitrogen; 1.2506 × 10 > Helium;
–3
–3
2 3
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1.764 × 10 > Hydrogen; 8.388 × 10 –5 5. (a) 10x y (b) x + x + x + 4
–4
6. –3x – 13x + 22 7. –x + 14x – 20
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Values and Life Skills
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1.12 × 10 8 8. x + 8y 9. –2x + 4x – 9x + 6
Exemplar Problems 10. − 11 x 2 + 7 xy + 11 y 2
3 2 2
1. c 2. d 3. False 4. False
Exercise 6.3
3 5
5. 2 × 5 , (2 ) , 2 2 + 3 , , 3 × 3 , 2 × 2 2 1. (a) 6 (b) 3 (c) 0 (d) 1
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2 3
0
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3 2
1 2. (a) –4 (b) –6 (c) –2 (d) 1
6. (a) a 7 (b) 7. 3 8. 1.44 × 10 m
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75 3. (a) 2 (b) 1 (c) 9 (d) 4
9. He has left power of 3 which is 5. 4. (a) 4 (b) –4 (c) 8 (d) 4
10. (a) 1 × 10 (b) 10 200 11. (–4) or 16 5. (a) 4 (b) 17 (c) –30
100
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Chapter 6 6. (a) p = –6 (b) p = 2 7. 8
Brainstorming
Exercise 6.1 (a) (iv) (b) (v) (c) (i) (d) (vi) (e) (ii) (f) (iii)
1. (a) 3x , 2x, 1 (b) a , 3a , 2a, 3
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2. (a) binomial (b) trinomial (c) binomial (d) trinomial Review Exercises
3 Multiple Choice Questions
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3. (a) –3 (b) 6yz (c) y z (d) –3yz 2
4 1. a 2. c 3. d 4. b 5. c
4. Terms with x 2 Coefficient of x 2 6. d 7. a 8. b
(a) –x y –y Solve Mentally
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(b) 3x yz 2 3yz 2 True or False
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(c) 3x y 3y
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(d) 20x y 20y 1. True 2. True 3. True 4. True 5. True
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