Subtract 7/42 from 7/90
7/90 - 7/42 is -4/45.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 42 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 90 × 7 = 630,
7/90 = 7 × 7/90 × 7 = 49/630 - Likewise, for the 2nd fraction, since 42 × 15 = 630,
7/42 = 7 × 15/42 × 15 = 105/630 - Subtract the two like fractions:
49/630 - 105/630 = 49 - 105/630 = -56/630 - After reducing the fraction, the answer is -4/45
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/90-7/42 7/90-14/42 7/90-7/84 21/90-7/42 7/90-21/42 35/90-7/42 7/90-35/42 49/90-7/42 7/90-49/42