Simplify the following expressions: 3a + 9b - 6 + 8a - 4b - 7a + 16. Class 7
hardSimplify the following expressions: 3a + 9b - 6 + 8a - 4b - 7a + 16. Class 7
Question 1.
Simplify the following expressions :
(a) 3a + 96 - 6 + 8a - 46 - 7a + 16
Solution:
= 3a + 8a - 7a + 96 - 46 - 6 + 16
= (3 + 8 - 7) a - (9 - 4) 6 + 10
= 4a + 56 + 10
(b) 3 (3a - 36) - 8a - 46 - 16
Solution:
3 (3a - 36) - 8a - 46 - 16
= 9a - 96 - 8a - 46 - 16
= 9a - 8a - 96 - 46 - 16
= a - 13b - 16
(c) 2 (2x - 3) + 8x + 12
Solution:
2 (2x - 3) + 8x + 12
= 4x - 6 + 8x + 12
= 4x + 8x - 6 + 12
= 12x + 6
(d) 8x - (2x - 3) + 12
Solution:
8x - (2x - 3) + 12
= 8x - 2x + 3 + 12
= 6x + 15
(e) 86 -(5 + 76) + 9
Solution:
8h -(5 + 7h) + 9
= 8h - 5 - 7h + 9
= 8h - 7h - 5 + 9
= h + 4
(f) 23 + 4(6m - 3a) -8a - 3m - 18
Solution:
23 + 4(6m - 3a) -8a - 3m - 18
= 23 + 24m - 12a -8a - 3m - 18
= 23 - 18 + 24m - 3m - 12a - 8a
= 5 + 21m - 20a
Question 2.
Add the expressions given below: Class 7
(a) 4d - 7c + 9. + 8c - 11 + 9d
Solution:
4d - 7c + 9. + 8c - 11 + 9d
= 4d + 9d - 7c + 8c + 9 - 11
= 13d + c - 2
(b) - 6f + 19 - 8s + (- 23 + 13f + 12s)
Solution:
- 6f + 19 - 8s + (- 23 + 13f + 12s)
= - 6f+ 19 - 8s - 23 + 13f+ 12s
= - 6f+ 13f - 8s + 12s + 19 - 23
= 7f + 4s - 4
(c) 8d - 14c + 9 + 16c - (11 + 9d)
Solution:
8d - 14c + 9 + 16c - (11 + 9d)
= 8d - 14c + 9 + 16c - 11 - 9d
= 8d - 9d - 14c + 16c - 9 - 11
= - d + 2c - 2
(d) 6f - 20 + 8s + 23 - 13f - 12s
Solution:
6f - 20 + 8s + 23 - 13f - 12s
= 6f - 13f + 8s - 12s - 20 + 23
= - 7f - 4s + 3
(e) 13m - 12n + 12n - 13m
Solution:
13m - 12n + 12n - 13m
= 13m - 13m - 12n + 12n
= 0 + 0 = 0.
(f) - 26m + 24a + 26m - 24a
Solution:
- 26m + 24a + 26m - 24a
= - 26m + 26m + 24n - 24n
= 0 + 0 = 0.