Page 232 - Maths Skills - 7

230 Maths

G. 1. City Distance (km) Distance (km) in 2. Planet Distance from Standard Notation
Exponential Form Sun (km)
Agra 256 2 8 Earth 149600000 1.496 × 10 8
Meerut 81 3 4 Jupiter 778300000 7.783 × 10 8
Kolkata 2401 7 4 Mars 22790000 2.279 × 10 8
Prayagraj 729 3 6 Venus 108200000 1.082 × 10 8
Thiruvananthpuram 6561 3 8 Saturn 142700000 1.427 × 10 9

HOTS

 3 14
1. 5 30 2.   3. 12,345.6; 1 × 10 + 2 × 10 + 3 × 10 + 4 × 10 + 5 × 10 + 6 × 10 4. 4.06 × 10 17
4
1
2
0
–1
3

5
Assessment - 2
6 4
1. (d) 2. (a) 3. (d) 4. (a) 5. (b) 6. = 7. – 3 8. ac
30 20
9. 4 10. 9 11. (F) 12. (T) 13. (T) 14. (F) 15. (T) 16. 1.9943 × 10 5
17. 8.5988 × 10 > 9.324 × 10 > 6.475 × 10 > 1.9943 × 10 > 1.554 × 10 18. 8.029 × 10 19. (a) 20. (d)
5
5
5
5
6
5
59 41 13
21. 22. a 8 23. (i) 6° (ii) 1.826 × 10 24. ` 1700 25. (a) − (b) − 26. (a) 12%
9
56 30 12
81
(b) 1,80,300 27. 202.5 litres, 450 km 28. 29. 0 30. ` 285
16
Chapter - 7: Algebraic Expressions
Boot-up
x
A. 1. (ii) 2. (iii) 3. (iii) 4. (iv) B. 1. 0 2. x = y + 7 3. 6y 4. x + = 8
3
C. 1. F 2. T 3. T 4. T
Exercise - 7.1
1. (i) Terms: 3a, – 7b, 6z, Factors: 3 × a, – 7 × b, 6 × z (ii) Terms: – 2a , + 5p, 4cd, Factors: – 2 × a × a, 5 × p, 4 × c × d
2
(iii) Terms: b , – 7t; Factors: b × b × b, – 7 × t (iv) Terms: 9a b, – 8ab , 2abc; Factors: 9 × a × a × b, – 8 × a × b × b, 2 × a × b × c
2
2
3
1
2. (i) 3xy – 4y + 7 (ii) 83xy – ab + 9b + 6 (iii) 6a – 4b + 8c + 19bc
3
2
2
2
3
7
3. (i) Binomial (ii) Monomial (iii) Trinomial (iv) Trinomial (v) Trinomial (vi) Binomial (vii) Monomial (viii) Trinomial
1
4. (i) (xy , 19y x) and (– 3xy, 4xy) (ii) (8p, p) and (8q, 90q) and (1pq, – 9pq)
2
2
3
1 1 1
(
(iii) (2x y, 16x y) and (– 13xy, yx) and (–15 abc, – abc) 5. (i) nx − y) (ii) p + q + p + q 3
3
3
3
3 17 5
a 15
(iii) 3b − (iv) 2x + 4 (v) x + 5y 6. (i) 2 (ii) 2 (iii) 3 (iv) 4 (v) 7 (vi) 3
b 2 4
Exercise - 7.2
1. (i) 6a – 6c + 3b (ii) 12x + 5x + 12 (iii) 6x – x + 24x + 9x + 10 (iv) 86t – 13t + 33 (v) 6p + 4pq + 5q 2
3
2
4
2
2
2
2
3
2
2. (i) 6x + 10 x + 20 (ii) 2p – 4q + 7pq (iii) 4 gh (iv) – 34x – 20x + 42 (v) – x + 3x + 2x – 7 3. – 5 34 a + 26b – 11c
2
3
2
2
2
3
4. – 11x + 13x – 14x 3 5. – 12x – 10x + 5x + 14 6. (i) 6x – 6x (ii) 7r – 3r + 20r (iii) 15v + 4v – 24v 2
3
2
5
3
4
5
4
5
4
(iv) – 9v – 2u + 2uv – 84 (v) 14x y + x – 6x 7. 2a – 2b + 3c 8. 3p + q – 5pq
2
3 2
2
2
2
2
9. 7m + 4p + 18q – 5m – 6 10. 2a + a b + 5ab 2
2
2
2
Exercise - 7.3
53
1. (i) – 8 (ii) – 18 (iii) – 151 (iv) 2 2. (i) – 9 (ii) 1 (iii) – 74 (iv) 2