Add 42/80 and 45/21
1st number: 42/80, 2nd number: 2 3/21
42/80 + 45/21 is 747/280.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 21 is 1680
Next, find the equivalent fraction of both fractional numbers with denominator 1680 - For the 1st fraction, since 80 × 21 = 1680,
42/80 = 42 × 21/80 × 21 = 882/1680 - Likewise, for the 2nd fraction, since 21 × 80 = 1680,
45/21 = 45 × 80/21 × 80 = 3600/1680 - Add the two like fractions:
882/1680 + 3600/1680 = 882 + 3600/1680 = 4482/1680 - 4482/1680 simplified gives 747/280
- So, 42/80 + 45/21 = 747/280
In mixed form: 2187/280
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/80+45/21 42/80+90/21 42/80+45/42 42/80+45/63