Addition of Rational Numbers

What are rational numbers?

A number of the form , where a and b are integer and b is not equal to zero is called rational numbers.

Addition of Rational Numbers

If the denominators of the given rational numbers are co-prime, then their LCM is the product of the denominators.

In general, if p/q and r/s are two rational numbers and q and s are co-primes, then

Examples

Find the sum

(I) -3/9 and 5/7        (ii) -4/3,8/9 and -3/8

Solution: (i) Here, 9 and 7 are co-primes.

as we know:

= 8/21