Add 42/45 and 45/21
1st number: 42/45, 2nd number: 2 3/21
42/45 + 45/21 is 323/105.
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,
42/45 = 42 × 7/45 × 7 = 294/315 - Likewise, for the 2nd fraction, since 21 × 15 = 315,
45/21 = 45 × 15/21 × 15 = 675/315 - Add the two like fractions:
294/315 + 675/315 = 294 + 675/315 = 969/315 - 969/315 simplified gives 323/105
- So, 42/45 + 45/21 = 323/105
In mixed form: 38/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/45+45/21 42/45+90/21 42/90+45/21 42/45+45/42 42/45+45/63