Answers

Solutions by everydaycalculation.com

Answers.everydaycalculation.com » Subtract fractions

Subtract 42/9 from 18/21

1st number: 18/21, 2nd number: 4 6/9

18/21 - 42/9 is -80/21.

Steps for subtracting fractions

  1. Find the least common denominator or LCM of the two denominators:
    LCM of 21 and 9 is 63

    Next, find the equivalent fraction of both fractional numbers with denominator 63
  2. For the 1st fraction, since 21 × 3 = 63,
    18/21 = 18 × 3/21 × 3 = 54/63
  3. Likewise, for the 2nd fraction, since 9 × 7 = 63,
    42/9 = 42 × 7/9 × 7 = 294/63
  4. Subtract the two like fractions:
    54/63 - 294/63 = 54 - 294/63 = -240/63
  5. After reducing the fraction, the answer is -80/21

MathStep (Works offline)

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

Related:

© everydaycalculation.com