Subtract 30/42 from 42/81
42/81 - 30/42 is -37/189.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 42 is 1134
Next, find the equivalent fraction of both fractional numbers with denominator 1134 - For the 1st fraction, since 81 × 14 = 1134,
42/81 = 42 × 14/81 × 14 = 588/1134 - Likewise, for the 2nd fraction, since 42 × 27 = 1134,
30/42 = 30 × 27/42 × 27 = 810/1134 - Subtract the two like fractions:
588/1134 - 810/1134 = 588 - 810/1134 = -222/1134 - After reducing the fraction, the answer is -37/189
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/81-30/42 42/81-60/42 42/81-30/84 42/81-90/42