Subtract 21/10 from 42/48, Solve 42/48

Subtract 21/10 from 42/48

1^st number: 42/48, 2^nd number: 2 1/10

42/48 - 21/10 is -49/40.

Find the least common denominator or LCM of the two denominators:
LCM of 48 and 10 is 240

Next, find the equivalent fraction of both fractional numbers with denominator 240
For the 1st fraction, since 48 × 5 = 240,
42/48 = 42 × 5/48 × 5 = 210/240
Likewise, for the 2nd fraction, since 10 × 24 = 240,
21/10 = 21 × 24/10 × 24 = 504/240
Subtract the two like fractions:
210/240 - 504/240 = 210 - 504/240 = -294/240
After reducing the fraction, the answer is -49/40

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