TN Class 8th Maths Solutions Chapter 1 Numbers Ex 1.3

From (3) and (4) a × b = b × a
Hence multiplication is commutative for rational numbers.

Question 3.
Verify the associative property for addition and multiplication for the rational numbers −7/9,5/6 and −4/3.
Answer:

From (1) and (2), (a + b) + c = a + (b + c) is true for rational numbers.

From (1) and (2) (a × b) × c = (a × b) × c is true for rational numbers.
Thus associative property.

Question 4.
Verify the distributive property a × (b + c) = (a × b) + (a + c) for the rational numbers a = −1/2, b = 2/3 and c = −5/6.
Answer:

From (1) and (2) we have a × (b + c) = (a × b) + (a × c) is true
Hence multiplication is distributive over addition for rational numbers Q.

Question 5.
Verify the identity property for addition and multiplication for the rational numbers 15/19 and −18/25.
Answer:

Identify property for addition verified.

Identify property for multiplication verified.

Question 6.
Verify the additive and multiplicative inverse property for the rational numbers −7/17 and 17/27.
Answer:

Additive inverse for rational numbers verified.

Mulplicative inverse for rational numbers verified.

Objective Type Questions

Question 7.
Closure property is not true for division of rational numbers because of the number
(A) 1
(B) 1
(C) 0
(D) 1/2
Answer:
(C) 0