Subtract 27/40 from 42/90
42/90 - 27/40 is -5/24.
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,
42/90 = 42 × 4/90 × 4 = 168/360 - Likewise, for the 2nd fraction, since 40 × 9 = 360,
27/40 = 27 × 9/40 × 9 = 243/360 - Subtract the two like fractions:
168/360 - 243/360 = 168 - 243/360 = -75/360 - After reducing the fraction, the answer is -5/24
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/90-27/40 42/90-54/40 42/90-27/80 42/90-81/40