Add 45/12 and 75/21
1st number: 3 9/12, 2nd number: 3 12/21
45/12 + 75/21 is 205/28.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 12 × 7 = 84,
45/12 = 45 × 7/12 × 7 = 315/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
75/21 = 75 × 4/21 × 4 = 300/84 - Add the two like fractions:
315/84 + 300/84 = 315 + 300/84 = 615/84 - 615/84 simplified gives 205/28
- So, 45/12 + 75/21 = 205/28
In mixed form: 79/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/12+75/21 45/24+75/21 45/12+75/42 45/36+75/21 45/12+75/63 45/60+75/21 45/84+75/21