Add 90/81 and 45/20
1st number: 1 9/81, 2nd number: 2 5/20
90/81 + 45/20 is 121/36.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 20 is 1620
Next, find the equivalent fraction of both fractional numbers with denominator 1620 - For the 1st fraction, since 81 × 20 = 1620,
90/81 = 90 × 20/81 × 20 = 1800/1620 - Likewise, for the 2nd fraction, since 20 × 81 = 1620,
45/20 = 45 × 81/20 × 81 = 3645/1620 - Add the two like fractions:
1800/1620 + 3645/1620 = 1800 + 3645/1620 = 5445/1620 - 5445/1620 simplified gives 121/36
- So, 90/81 + 45/20 = 121/36
In mixed form: 313/36
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/81+90/20 90/81+45/40 90/81+45/60