Subtract 7/15 from 42/21, Solve 2 0/21

Subtract 7/15 from 42/21

1^st number: 2 0/21, 2^nd number: 7/15

42/21 - 7/15 is 23/15.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 15 is 105

Next, find the equivalent fraction of both fractional numbers with denominator 105
For the 1st fraction, since 21 × 5 = 105,
42/21 = 42 × 5/21 × 5 = 210/105
Likewise, for the 2nd fraction, since 15 × 7 = 105,
7/15 = 7 × 7/15 × 7 = 49/105
Subtract the two like fractions:
210/105 - 49/105 = 210 - 49/105 = 161/105
After reducing the fraction, the answer is 23/15
In mixed form: 18/15

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