Add 45/90 and 15/21
45/90 + 15/21 is 17/14.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 21 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 90 × 7 = 630,
45/90 = 45 × 7/90 × 7 = 315/630 - Likewise, for the 2nd fraction, since 21 × 30 = 630,
15/21 = 15 × 30/21 × 30 = 450/630 - Add the two like fractions:
315/630 + 450/630 = 315 + 450/630 = 765/630 - 765/630 simplified gives 17/14
- So, 45/90 + 15/21 = 17/14
In mixed form: 13/14
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 45/90+30/21 45/90+15/42 45/90+45/21 45/90+15/63 45/90+75/21