Add 81/40 and 70/21
1st number: 2 1/40, 2nd number: 3 7/21
81/40 + 70/21 is 643/120.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 21 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 40 × 21 = 840,
81/40 = 81 × 21/40 × 21 = 1701/840 - Likewise, for the 2nd fraction, since 21 × 40 = 840,
70/21 = 70 × 40/21 × 40 = 2800/840 - Add the two like fractions:
1701/840 + 2800/840 = 1701 + 2800/840 = 4501/840 - 4501/840 simplified gives 643/120
- So, 81/40 + 70/21 = 643/120
In mixed form: 543/120
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