Subtract 21/15 from 24/42, Solve 24/42

Subtract 21/15 from 24/42

1^st number: 24/42, 2^nd number: 1 6/15

24/42 - 21/15 is -29/35.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 15 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 42 × 5 = 210,
24/42 = 24 × 5/42 × 5 = 120/210
Likewise, for the 2nd fraction, since 15 × 14 = 210,
21/15 = 21 × 14/15 × 14 = 294/210
Subtract the two like fractions:
120/210 - 294/210 = 120 - 294/210 = -174/210
After reducing the fraction, the answer is -29/35

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