Add 20/40 and 45/42
1st number: 20/40, 2nd number: 1 3/42
20/40 + 45/42 is 11/7.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 42 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 40 × 21 = 840,
20/40 = 20 × 21/40 × 21 = 420/840 - Likewise, for the 2nd fraction, since 42 × 20 = 840,
45/42 = 45 × 20/42 × 20 = 900/840 - Add the two like fractions:
420/840 + 900/840 = 420 + 900/840 = 1320/840 - 1320/840 simplified gives 11/7
- So, 20/40 + 45/42 = 11/7
In mixed form: 14/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 20/40+90/42 20/80+45/42 20/40+45/84 60/40+45/42