Subtract 30/70 from 12/45
12/45 - 30/70 is -17/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 70 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 45 × 14 = 630,
12/45 = 12 × 14/45 × 14 = 168/630 - Likewise, for the 2nd fraction, since 70 × 9 = 630,
30/70 = 30 × 9/70 × 9 = 270/630 - Subtract the two like fractions:
168/630 - 270/630 = 168 - 270/630 = -102/630 - After reducing the fraction, the answer is -17/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/45-30/70 12/45-60/70 12/90-30/70 36/45-30/70 12/45-90/70 60/45-30/70 84/45-30/70