Subtract 15/30 from 28/21, Solve 1 7/21

Subtract 15/30 from 28/21

1^st number: 1 7/21, 2^nd number: 15/30

28/21 - 15/30 is 5/6.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 30 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 21 × 10 = 210,
28/21 = 28 × 10/21 × 10 = 280/210
Likewise, for the 2nd fraction, since 30 × 7 = 210,
15/30 = 15 × 7/30 × 7 = 105/210
Subtract the two like fractions:
280/210 - 105/210 = 280 - 105/210 = 175/210
After reducing the fraction, the answer is 5/6

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