Add 12/21 and 25/45
12/21 + 25/45 is 71/63.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 45 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 21 × 15 = 315,
12/21 = 12 × 15/21 × 15 = 180/315 - Likewise, for the 2nd fraction, since 45 × 7 = 315,
25/45 = 25 × 7/45 × 7 = 175/315 - Add the two like fractions:
180/315 + 175/315 = 180 + 175/315 = 355/315 - 355/315 simplified gives 71/63
- So, 12/21 + 25/45 = 71/63
In mixed form: 18/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/21+25/45 12/21+50/45 12/42+25/45 12/21+25/90 36/21+25/45 12/21+75/45 12/63+25/45 60/21+25/45 84/21+25/45