Answers

Subtract 1/42 from 42/80

42/80 - 1/42 is 421/840.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 80 and 42 is 1680
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1680
2. For the 1st fraction, since 80 × 21 = 1680,
   42/80 = 42 × 21/80 × 21 = 882/1680
3. Likewise, for the 2nd fraction, since 42 × 40 = 1680,
   1/42 = 1 × 40/42 × 40 = 40/1680
4. Subtract the two like fractions:
   882/1680 - 40/1680 = 882 - 40/1680 = 842/1680
5. After reducing the fraction, the answer is 421/840

MathStep (Works offline)

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

Related: ⁸⁴/₈₀-¹/₄₂ ⁴²/₈₀-²/₄₂ ⁴²/₈₀-¹/₈₄ ⁴²/₈₀-³/₄₂ ⁴²/₈₀-⁵/₄₂ ⁴²/₈₀-⁷/₄₂

Subtract Fractions Calculator