Subtract 18/8 from 42/84
1st number: 42/84, 2nd number: 2 2/8
42/84 - 18/8 is -7/4.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 8 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 84 × 2 = 168,
42/84 = 42 × 2/84 × 2 = 84/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
18/8 = 18 × 21/8 × 21 = 378/168 - Subtract the two like fractions:
84/168 - 378/168 = 84 - 378/168 = -294/168 - After reducing the fraction, the answer is -7/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/84-36/8 42/84-18/16 42/84-54/8 42/84-18/24 42/84-90/8 42/84-18/40 42/84-18/56