Subtract 70/90 from 42/84
42/84 - 70/90 is -5/18.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 90 is 1260
Next, find the equivalent fraction of both fractional numbers with denominator 1260 - For the 1st fraction, since 84 × 15 = 1260,
42/84 = 42 × 15/84 × 15 = 630/1260 - Likewise, for the 2nd fraction, since 90 × 14 = 1260,
70/90 = 70 × 14/90 × 14 = 980/1260 - Subtract the two like fractions:
630/1260 - 980/1260 = 630 - 980/1260 = -350/1260 - After reducing the fraction, the answer is -5/18
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: