Answers

Subtract 72/10 from 21/5

1^st number: 4 1/5, 2^nd number: 7 2/10

21/5 - 72/10 is -3/1.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 5 and 10 is 10
   
   Next, find the equivalent fraction of both fractional numbers with denominator 10
2. For the 1st fraction, since 5 × 2 = 10,
   21/5 = 21 × 2/5 × 2 = 42/10
3. Likewise, for the 2nd fraction, since 10 × 1 = 10,
   72/10 = 72 × 1/10 × 1 = 72/10
4. Subtract the two like fractions:
   42/10 - 72/10 = 42 - 72/10 = -30/10
5. After reducing the fraction, the answer is -3/1

MathStep (Works offline)

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

Related: ⁴²/₅-⁷²/₁₀ ²¹/₁₀-⁷²/₁₀ ²¹/₅-⁷²/₂₀ ⁶³/₅-⁷²/₁₀ ²¹/₁₅-⁷²/₁₀ ²¹/₅-⁷²/₃₀ ²¹/₂₅-⁷²/₁₀ ²¹/₅-⁷²/₅₀ ²¹/₃₅-⁷²/₁₀ ²¹/₅-⁷²/₇₀

Subtract Fractions Calculator