The reciprocal of the sum of reciprocal of both the rational number 2/r and 3/r will be, where r≠0
Answers
Answer:
It can't be reciporcal
Answer:
. Add the following:
(i) 4 / 7 and 5 / 7
(ii) 7 / – 13 and 4 / – 13
Solution:
(i) Given
4 / 7 and 5 / 7
Adding both the numbers
4 / 7 + 5 / 7 = (4 + 5) / 7
We get,
= 9 / 7
∴ The addition of 4 / 7 and 5 / 7 is 9 / 7
(ii) Given
7 / – 13 and 4 / – 13
Consider
7 / – 13 = {7 × (-1)} / {- 13 × (-1)}
= – 7 / 13
Also,
4 / – 13 = {4 × (-1)} / {- 13 × (-1)}
= – 4 / 13
Now,
Adding both the numbers
(7 / – 13) + (4 / – 13) = (- 7 – 4) / 13
We get,
= – 11 / 13
2. Simplify:
(i) 5 / 11 + 
(ii) – 4 / 9 + 
Solution:
(i) Given
5 / 11 +

This can be written as,
5 / 11 + 39 / 9
Taking L.C.M we get,
5 / 11 = (5 × 9) / (11 × 9)
We get,
= 45 / 99
39 / 9 = (39 × 11) / (9 × 11)
We get,
= 429 / 99
Now,
Adding both the numbers,
45 / 99 + 429 / 99 = (45 + 429) / 99
= 474 / 99

=

Dividing numerator and denominator by 3,
= 4 (78 ÷ 3) / (99 ÷ 3)
We get,
=

(ii) Given
– 4 / 9 +

This can be written as,
– 4 / 9 + 38 / 13
Taking L.C.M we get,
– 4 / 9 = (-4 × 13) / (9 × 13)
We get,
= – 52 / 117
38 / 13 = (38 × 9) / (13 × 9)
We get,
= 342 / 117
Now,
Adding both the numbers,
– 52 / 117 + 342 / 117 = (- 52 + 342) / 117
We get,
= 290 / 117

=