Add 15/45 and 21/42
15/45 + 21/42 is 5/6.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 42 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 45 × 14 = 630,
15/45 = 15 × 14/45 × 14 = 210/630 - Likewise, for the 2nd fraction, since 42 × 15 = 630,
21/42 = 21 × 15/42 × 15 = 315/630 - Add the two like fractions:
210/630 + 315/630 = 210 + 315/630 = 525/630 - 525/630 simplified gives 5/6
- So, 15/45 + 21/42 = 5/6
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/45+21/42 15/90+21/42 15/45+21/84 15/45+63/42 75/45+21/42