Add 40/84 and 15/21
40/84 + 15/21 is 25/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 84 × 1 = 84,
40/84 = 40 × 1/84 × 1 = 40/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
15/21 = 15 × 4/21 × 4 = 60/84 - Add the two like fractions:
40/84 + 60/84 = 40 + 60/84 = 100/84 - 100/84 simplified gives 25/21
- So, 40/84 + 15/21 = 25/21
In mixed form: 14/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/84+15/21 40/84+30/21 40/84+15/42 40/84+45/21 40/84+15/63 40/84+75/21