Answers

Subtract 16/81 from 21/28

21/28 - 16/81 is 179/324.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 28 and 81 is 2268
   
   Next, find the equivalent fraction of both fractional numbers with denominator 2268
2. For the 1st fraction, since 28 × 81 = 2268,
   21/28 = 21 × 81/28 × 81 = 1701/2268
3. Likewise, for the 2nd fraction, since 81 × 28 = 2268,
   16/81 = 16 × 28/81 × 28 = 448/2268
4. Subtract the two like fractions:
   1701/2268 - 448/2268 = 1701 - 448/2268 = 1253/2268
5. After reducing the fraction, the answer is 179/324

MathStep (Works offline)

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

Related: ⁴²/₂₈-¹⁶/₈₁ ²¹/₂₈-³²/₈₁ ²¹/₅₆-¹⁶/₈₁ ⁶³/₂₈-¹⁶/₈₁ ²¹/₂₈-⁴⁸/₈₁ ²¹/₈₄-¹⁶/₈₁ ²¹/₂₈-⁸⁰/₈₁

Subtract Fractions Calculator