Add 12/45 and 75/21
1st number: 12/45, 2nd number: 3 12/21
12/45 + 75/21 is 403/105.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 21 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 45 × 7 = 315,
12/45 = 12 × 7/45 × 7 = 84/315 - Likewise, for the 2nd fraction, since 21 × 15 = 315,
75/21 = 75 × 15/21 × 15 = 1125/315 - Add the two like fractions:
84/315 + 1125/315 = 84 + 1125/315 = 1209/315 - 1209/315 simplified gives 403/105
- So, 12/45 + 75/21 = 403/105
In mixed form: 388/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/45+75/21 12/90+75/21 12/45+75/42 36/45+75/21 12/45+75/63 60/45+75/21 84/45+75/21