Answers

Subtract 21/7 from 15/12

1^st number: 1 3/12, 2^nd number: 3 0/7

15/12 - 21/7 is -7/4.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 12 and 7 is 84
   
   Next, find the equivalent fraction of both fractional numbers with denominator 84
2. For the 1st fraction, since 12 × 7 = 84,
   15/12 = 15 × 7/12 × 7 = 105/84
3. Likewise, for the 2nd fraction, since 7 × 12 = 84,
   21/7 = 21 × 12/7 × 12 = 252/84
4. Subtract the two like fractions:
   105/84 - 252/84 = 105 - 252/84 = -147/84
5. After reducing the fraction, the answer is -7/4

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad

Related: ³⁰/₁₂-²¹/₇ ¹⁵/₁₂-⁴²/₇ ¹⁵/₂₄-²¹/₇ ¹⁵/₁₂-²¹/₁₄ ⁴⁵/₁₂-²¹/₇ ¹⁵/₁₂-⁶³/₇ ¹⁵/₃₆-²¹/₇ ⁷⁵/₁₂-²¹/₇ ¹⁵/₆₀-²¹/₇ ¹⁵/₁₂-²¹/₃₅ ¹⁵/₈₄-²¹/₇ ¹⁵/₁₂-²¹/₄₉

Subtract Fractions Calculator