Subtract 28/8 from 21/60, Solve 21/60

Subtract 28/8 from 21/60

1^st number: 21/60, 2^nd number: 3 4/8

21/60 - 28/8 is -63/20.

Find the least common denominator or LCM of the two denominators:
LCM of 60 and 8 is 120

Next, find the equivalent fraction of both fractional numbers with denominator 120
For the 1st fraction, since 60 × 2 = 120,
21/60 = 21 × 2/60 × 2 = 42/120
Likewise, for the 2nd fraction, since 8 × 15 = 120,
28/8 = 28 × 15/8 × 15 = 420/120
Subtract the two like fractions:
42/120 - 420/120 = 42 - 420/120 = -378/120
After reducing the fraction, the answer is -63/20

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