Subtract 42/8 from 72/84
1st number: 72/84, 2nd number: 5 2/8
72/84 - 42/8 is -123/28.
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,
72/84 = 72 × 2/84 × 2 = 144/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
42/8 = 42 × 21/8 × 21 = 882/168 - Subtract the two like fractions:
144/168 - 882/168 = 144 - 882/168 = -738/168 - After reducing the fraction, the answer is -123/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/84-84/8 72/84-42/16 72/84-42/24 72/84-42/40 72/84-42/56