Add 15/45 and 30/42
15/45 + 30/42 is 22/21.
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,
30/42 = 30 × 15/42 × 15 = 450/630 - Add the two like fractions:
210/630 + 450/630 = 210 + 450/630 = 660/630 - 660/630 simplified gives 22/21
- So, 15/45 + 30/42 = 22/21
In mixed form: 11/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/45+30/42 15/45+60/42 15/90+30/42 15/45+30/84 15/45+90/42 75/45+30/42