How do you add rational numbers with different denominators?
GeneralClass 12AllAnswered 27 Mar 2026
Answer
Use the cross-multiplication method or LCM method.
Formula: p/q + r/s = (p × s + r × q)/(q × s)
Example: Add 2/3 + 5/6
Step 1: Find LCM(3, 6) = 6
Step 2: Convert to equivalent fractions
- 2/3 = 4/6
- 5/6 = 5/6
Step 3: Add numerators
- 4/6 + 5/6 = 9/6 = 3/2
Answer: 3/2
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