Add 30/70 and 42/72
30/70 + 42/72 is 85/84.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 72 is 2520
Next, find the equivalent fraction of both fractional numbers with denominator 2520 - For the 1st fraction, since 70 × 36 = 2520,
30/70 = 30 × 36/70 × 36 = 1080/2520 - Likewise, for the 2nd fraction, since 72 × 35 = 2520,
42/72 = 42 × 35/72 × 35 = 1470/2520 - Add the two like fractions:
1080/2520 + 1470/2520 = 1080 + 1470/2520 = 2550/2520 - 2550/2520 simplified gives 85/84
- So, 30/70 + 42/72 = 85/84
In mixed form: 11/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/70+42/72 30/70+84/72 90/70+42/72