Add 21/40 and 45/42
1st number: 21/40, 2nd number: 1 3/42
21/40 + 45/42 is 447/280.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 42 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 40 × 21 = 840,
21/40 = 21 × 21/40 × 21 = 441/840 - Likewise, for the 2nd fraction, since 42 × 20 = 840,
45/42 = 45 × 20/42 × 20 = 900/840 - Add the two like fractions:
441/840 + 900/840 = 441 + 900/840 = 1341/840 - 1341/840 simplified gives 447/280
- So, 21/40 + 45/42 = 447/280
In mixed form: 1167/280
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