Add 72/20 and 21/45
1st number: 3 12/20, 2nd number: 21/45
72/20 + 21/45 is 61/15.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 45 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 20 × 9 = 180,
72/20 = 72 × 9/20 × 9 = 648/180 - Likewise, for the 2nd fraction, since 45 × 4 = 180,
21/45 = 21 × 4/45 × 4 = 84/180 - Add the two like fractions:
648/180 + 84/180 = 648 + 84/180 = 732/180 - 732/180 simplified gives 61/15
- So, 72/20 + 21/45 = 61/15
In mixed form: 41/15
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