Answer:
Step I: Let us obtain the rational numbers and see whether their denominators are positive or not. If the denominator of one (or both) of the numerators is negative, re-arrange it so that the denominators become positive.
Step II: Obtain the denominators of the rational numbers in step I.
Step III: Find the lowest common multiple of the denominators of the two given rational numbers.
Step IV: Express both the rational numbers in step I so that the lowest common multiple of the denominators becomes their common denominator.
Step V: Write a rational number whose numerator is equal to the sum of the numerators of rational numbers obtained in step IV and denominators is the lowest common multiple obtained in step III.
Step VI: The rational number obtained in step V is the required sum (simplify if required).