Subtract 84/45 from 30/42
1st number: 30/42, 2nd number: 1 39/45
30/42 - 84/45 is -121/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 45 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 42 × 15 = 630,
30/42 = 30 × 15/42 × 15 = 450/630 - Likewise, for the 2nd fraction, since 45 × 14 = 630,
84/45 = 84 × 14/45 × 14 = 1176/630 - Subtract the two like fractions:
450/630 - 1176/630 = 450 - 1176/630 = -726/630 - After reducing the fraction, the answer is -121/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/42-84/45 30/84-84/45 30/42-84/90 90/42-84/45