Add 81/42 and 70/90
1st number: 1 39/42, 2nd number: 70/90
81/42 + 70/90 is 341/126.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 90 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 42 × 15 = 630,
81/42 = 81 × 15/42 × 15 = 1215/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
70/90 = 70 × 7/90 × 7 = 490/630 - Add the two like fractions:
1215/630 + 490/630 = 1215 + 490/630 = 1705/630 - 1705/630 simplified gives 341/126
- So, 81/42 + 70/90 = 341/126
In mixed form: 289/126
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/84+70/90