CLASS-7
ADDITION OF RATIONAL NUMBER WITH SAME DENOMINATOR

ADDITION OF RATIONAL NUMBER WITH SAME DENOMINATOR -

1. If a/b and c/b are two rational numbers with the same denominator, then a/b + c/b = (a+c)/b.

1. Find the sum 7/9 + −11/9.

Solution:

7/9 + −11/9

= 7+(−11)/9

= (7−11)/9

= −4/9         (Ans.)


2. Find the sum 8/−11 + 3/11

Solution:

We first express 8/−11 as a rational number with positive denominator.

We have, 8/−11 = 8×(−1)/(−11)×(−1) = −8/11.

Therefore, 8/−11 + 3/11

= (−8/11 + 3/11)

= (−8+3)/11

= −5/11           (Ans.)