Subtract 18/40 from 42/50
42/50 - 18/40 is 39/100.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 50 and 40 is 200
Next, find the equivalent fraction of both fractional numbers with denominator 200 - For the 1st fraction, since 50 × 4 = 200,
42/50 = 42 × 4/50 × 4 = 168/200 - Likewise, for the 2nd fraction, since 40 × 5 = 200,
18/40 = 18 × 5/40 × 5 = 90/200 - Subtract the two like fractions:
168/200 - 90/200 = 168 - 90/200 = 78/200 - After reducing the fraction, the answer is 39/100
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/50-18/40 42/50-36/40 42/50-18/80 42/50-54/40 42/50-90/40