Add 4/21 and 40/45
4/21 + 40/45 is 68/63.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 45 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 21 × 15 = 315,
4/21 = 4 × 15/21 × 15 = 60/315 - Likewise, for the 2nd fraction, since 45 × 7 = 315,
40/45 = 40 × 7/45 × 7 = 280/315 - Add the two like fractions:
60/315 + 280/315 = 60 + 280/315 = 340/315 - 340/315 simplified gives 68/63
- So, 4/21 + 40/45 = 68/63
In mixed form: 15/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 8/21+40/45 4/21+80/45 4/42+40/45 4/21+40/90 12/21+40/45 4/63+40/45 20/21+40/45 28/21+40/45