Add 45/70 and 21/90
45/70 + 21/90 is 92/105.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 90 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 70 × 9 = 630,
45/70 = 45 × 9/70 × 9 = 405/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
21/90 = 21 × 7/90 × 7 = 147/630 - Add the two like fractions:
405/630 + 147/630 = 405 + 147/630 = 552/630 - 552/630 simplified gives 92/105
- So, 45/70 + 21/90 = 92/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/70+21/90 45/70+42/90 45/70+63/90