Add 20/42 and 21/40
20/42 + 21/40 is 841/840.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 42 × 20 = 840,
20/42 = 20 × 20/42 × 20 = 400/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
21/40 = 21 × 21/40 × 21 = 441/840 - Add the two like fractions:
400/840 + 441/840 = 400 + 441/840 = 841/840 - So, 20/42 + 21/40 = 841/840
In mixed form: 11/840
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