Add 40/42 and 30/70
40/42 + 30/70 is 29/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 70 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 42 × 5 = 210,
40/42 = 40 × 5/42 × 5 = 200/210 - Likewise, for the 2nd fraction, since 70 × 3 = 210,
30/70 = 30 × 3/70 × 3 = 90/210 - Add the two like fractions:
200/210 + 90/210 = 200 + 90/210 = 290/210 - 290/210 simplified gives 29/21
- So, 40/42 + 30/70 = 29/21
In mixed form: 18/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/42+30/70 40/42+60/70 40/84+30/70 40/42+90/70