Add 42/90 and 30/81
42/90 + 30/81 is 113/135.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 81 is 810
Next, find the equivalent fraction of both fractional numbers with denominator 810 - For the 1st fraction, since 90 × 9 = 810,
42/90 = 42 × 9/90 × 9 = 378/810 - Likewise, for the 2nd fraction, since 81 × 10 = 810,
30/81 = 30 × 10/81 × 10 = 300/810 - Add the two like fractions:
378/810 + 300/810 = 378 + 300/810 = 678/810 - 678/810 simplified gives 113/135
- So, 42/90 + 30/81 = 113/135
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/90+30/81 42/90+60/81 42/90+90/81