Question

verify the commutative property of addition of the following pair of rational numbers. (a) -8/9 and3/5 (b) 3/4 and1/3

Answer 1

Answer:

a ) LHS :

a + b = - 8 / 9 + 3 / 5 .

LCM of 9 , 5 is 45 .

- 8 × 5 / 9× 5 = - 40 / 45 .

3 × 9 / 5 × 9 = 27 / 45 .

= - 40 / 45 + 27 / 45 .

= - 40 + 27 / 45 .

= - 13 / 45 .

RHS :

b + a = 3 / 5 + - 8 / 9 .

LCM of 5 , 9 is 45 .

3 × 9 / 5 × 9 = 27 / 45 .

- 8 × 5 / 9 × 5 = - 40 / 45 .

= 27 / 45 + ( - 40 / 45 ) .

= 27 + ( - 40 ) / 45 .

= - 13 / 45 .

- 13 / 45 = - 13 / 45 .

LHS = RHS .

a + b = b + a .

Hence proved .