Subtract 20/40 from 8/90
8/90 - 20/40 is -37/90.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 40 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 90 × 4 = 360,
8/90 = 8 × 4/90 × 4 = 32/360 - Likewise, for the 2nd fraction, since 40 × 9 = 360,
20/40 = 20 × 9/40 × 9 = 180/360 - Subtract the two like fractions:
32/360 - 180/360 = 32 - 180/360 = -148/360 - After reducing the fraction, the answer is -37/90
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 16/90-20/40 8/90-20/80 24/90-20/40 8/90-60/40 40/90-20/40 56/90-20/40