Add 45/15 and 20/21
1st number: 3 0/15, 2nd number: 20/21
45/15 + 20/21 is 83/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 21 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 15 × 7 = 105,
45/15 = 45 × 7/15 × 7 = 315/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
20/21 = 20 × 5/21 × 5 = 100/105 - Add the two like fractions:
315/105 + 100/105 = 315 + 100/105 = 415/105 - 415/105 simplified gives 83/21
- So, 45/15 + 20/21 = 83/21
In mixed form: 320/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/15+20/21 45/15+40/21 45/30+20/21 45/15+20/42 45/15+60/21 45/15+20/63 45/75+20/21