Subtract 18/20 from 63/90
63/90 - 18/20 is -1/5.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 20 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 90 × 2 = 180,
63/90 = 63 × 2/90 × 2 = 126/180 - Likewise, for the 2nd fraction, since 20 × 9 = 180,
18/20 = 18 × 9/20 × 9 = 162/180 - Subtract the two like fractions:
126/180 - 162/180 = 126 - 162/180 = -36/180 - After reducing the fraction, the answer is -1/5
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 63/90-36/20 63/90-18/40 63/90-54/20 63/90-18/60 63/90-90/20