Add 21/45 and 15/70
21/45 + 15/70 is 143/210.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 70 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 45 × 14 = 630,
21/45 = 21 × 14/45 × 14 = 294/630 - Likewise, for the 2nd fraction, since 70 × 9 = 630,
15/70 = 15 × 9/70 × 9 = 135/630 - Add the two like fractions:
294/630 + 135/630 = 294 + 135/630 = 429/630 - 429/630 simplified gives 143/210
- So, 21/45 + 15/70 = 143/210
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/45+15/70 21/45+30/70 21/90+15/70 63/45+15/70 21/45+45/70 21/45+75/70