Subtract 30/80 from 40/42
40/42 - 30/80 is 97/168.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 80 is 1680
Next, find the equivalent fraction of both fractional numbers with denominator 1680 - For the 1st fraction, since 42 × 40 = 1680,
40/42 = 40 × 40/42 × 40 = 1600/1680 - Likewise, for the 2nd fraction, since 80 × 21 = 1680,
30/80 = 30 × 21/80 × 21 = 630/1680 - Subtract the two like fractions:
1600/1680 - 630/1680 = 1600 - 630/1680 = 970/1680 - After reducing the fraction, the answer is 97/168
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/42-30/80 40/42-60/80 40/84-30/80 40/42-90/80