Subtract 12/90 from 28/40
28/40 - 12/90 is 17/30.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 90 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 40 × 9 = 360,
28/40 = 28 × 9/40 × 9 = 252/360 - Likewise, for the 2nd fraction, since 90 × 4 = 360,
12/90 = 12 × 4/90 × 4 = 48/360 - Subtract the two like fractions:
252/360 - 48/360 = 252 - 48/360 = 204/360 - After reducing the fraction, the answer is 17/30
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/40-12/90 28/40-24/90 28/80-12/90 84/40-12/90 28/40-36/90 28/40-60/90 28/40-84/90