Answers

Subtract 27/35 from 21/42

21/42 - 27/35 is -19/70.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 42 and 35 is 210
   
   Next, find the equivalent fraction of both fractional numbers with denominator 210
2. For the 1st fraction, since 42 × 5 = 210,
   21/42 = 21 × 5/42 × 5 = 105/210
3. Likewise, for the 2nd fraction, since 35 × 6 = 210,
   27/35 = 27 × 6/35 × 6 = 162/210
4. Subtract the two like fractions:
   105/210 - 162/210 = 105 - 162/210 = -57/210
5. After reducing the fraction, the answer is -19/70

MathStep (Works offline)

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

Related: ²¹/₄₂-⁵⁴/₃₅ ²¹/₈₄-²⁷/₃₅ ²¹/₄₂-²⁷/₇₀ ⁶³/₄₂-²⁷/₃₅ ²¹/₄₂-⁸¹/₃₅

Subtract Fractions Calculator