Add 21/70 and 28/90
21/70 + 28/90 is 11/18.
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,
21/70 = 21 × 9/70 × 9 = 189/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
28/90 = 28 × 7/90 × 7 = 196/630 - Add the two like fractions:
189/630 + 196/630 = 189 + 196/630 = 385/630 - 385/630 simplified gives 11/18
- So, 21/70 + 28/90 = 11/18
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