Add 15/21 and 28/40
15/21 + 28/40 is 99/70.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 21 × 40 = 840,
15/21 = 15 × 40/21 × 40 = 600/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
28/40 = 28 × 21/40 × 21 = 588/840 - Add the two like fractions:
600/840 + 588/840 = 600 + 588/840 = 1188/840 - 1188/840 simplified gives 99/70
- So, 15/21 + 28/40 = 99/70
In mixed form: 129/70
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