Subtract 4/90 from 70/80
70/80 - 4/90 is 299/360.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 90 is 720
Next, find the equivalent fraction of both fractional numbers with denominator 720 - For the 1st fraction, since 80 × 9 = 720,
70/80 = 70 × 9/80 × 9 = 630/720 - Likewise, for the 2nd fraction, since 90 × 8 = 720,
4/90 = 4 × 8/90 × 8 = 32/720 - Subtract the two like fractions:
630/720 - 32/720 = 630 - 32/720 = 598/720 - After reducing the fraction, the answer is 299/360
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/80-8/90 70/80-12/90 70/80-20/90 70/80-28/90