Subtract 48/12 from 21/40, Solve 21/40

Subtract 48/12 from 21/40

1^st number: 21/40, 2^nd number: 4 0/12

21/40 - 48/12 is -139/40.

Find the least common denominator or LCM of the two denominators:
LCM of 40 and 12 is 120

Next, find the equivalent fraction of both fractional numbers with denominator 120
For the 1st fraction, since 40 × 3 = 120,
21/40 = 21 × 3/40 × 3 = 63/120
Likewise, for the 2nd fraction, since 12 × 10 = 120,
48/12 = 48 × 10/12 × 10 = 480/120
Subtract the two like fractions:
63/120 - 480/120 = 63 - 480/120 = -417/120
After reducing the fraction, the answer is -139/40

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