## ML Aggarwal Class 8 Solutions for ICSE Maths Chapter 1 Rational Numbers Ex 1.2

Question 1.

Subtract:

Solution:

Question 2.

Sum of two rational numbers is \(\frac { 3 }{ 5 }\). If one of them is \(\frac { -2 }{ 7 }\), find the other.

Solution:

Sum of two rational numbers = \(\frac { 3 }{ 5 }\)

One number = \(\frac { -2 }{ 7 }\)

Question 3.

What rational number should be added to \(\frac { -5 }{ 11 }\) to get \(\frac { -7 }{ 8 }\)?

Solution:

Sum of two numbers = \(\frac { -7 }{ 8 }\)

One number = \(\frac { -5 }{ 11 }\)

Question 4.

What rational number should be subtracted from -4\(\frac { 3 }{ 5 }\) to get -3\(\frac { 1 }{ 2 }\) ?

Solution:

Question 5.

Subtract the sum of \(\frac { -5 }{ 7 }\) and \(\frac { -8 }{ 3 }\) from the sum of \(\frac { 5 }{ 2 }\) and \(\frac { -11 }{ 12 }\).

Solution:

Question 6.

If x = \(\frac { -4 }{ 7 }\) and y = \(\frac { 2 }{ 5 }\), then verify that x – y ≠ y – x.

Solution:

Question 7.

If x = \(\frac { 4 }{ 9 }\), y = \(\frac { -7 }{ 12 }\) and z = \(\frac { -2 }{ 3 }\), then verify that x – (y – z) ≠ (x – y) – z

Solution:

Question 8.

Which of the following statement is true/fasle?

(i) \(\frac { 2 }{ 3 } -\frac { 4 }{ 5 }\) is not a rational number.

(ii) \(\frac { -5 }{ 7 }\) is the additive inverse of \(\frac { 5 }{ 7 }\).

(iii) 0 is the additive inverse of its own.

(iv) Commutative property holds for subtraction of rational numbers.

(v) Associative property does not hold for subtraction of rational numbers.

(vi) 0 is the identity element for subtraction of rational numbers.

Solution:

(i) \(\frac { 2 }{ 3 } -\frac { 4 }{ 5 }\) is not a rational number. (False)

Correct:

\(\frac { 10-12 }{ 15 }\) = \(\frac { -2 }{ 15 }\)

It is a rational number.

(ii) \(\frac { -5 }{ 7 }\) is the additive inverse of \(\frac { 5 }{ 7 }\). (True)

(iii) 0 is the additive inverse of its own. (True)

(iv) Commutative property holds for subtraction of rational numbers. (False)

(v) Associative property does not hold for subtraction of rational numbers. (True)

(vi) 0 is the identity element for subtraction of rational numbers. (False)