Question

5. Take a = -6, b = 9.c = 5 and verify that ( a + b = b + a (ii) a-b=b-a (i) a + (b + c) = (a + b) + c ​

Answer 1

Given:

• a = -6
• b = 9
• c = 5

To verify:

• (a + b) = (b + a)
• (a - b) = (b - a)
• a + (b + c) = (a + b) + c

Solution:

(a + b) = (b + a)

⇒ -6 + 9 = 9 - 6

⇒ 3 = 3

Hence First part of this question is verified.

(a - b) = (b - a)

⇒ -6 - 9 ≠ 9 - (-6)

⇒ -15 ≠ 15

Commutative property holds good only for addition and multiplication but not for subtraction.

So second part of this question cannot be verified.

a + (b + c) = (a + b) + c

⇒ -6 + (9 + 5) = (-6 + 9) + 5

⇒ -6 + 14 = 3 + 5

⇒ 8 = 8

Hence third part of this question is verified.