Add 21/90 and 12/70
21/90 + 12/70 is 17/42.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 70 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 90 × 7 = 630,
21/90 = 21 × 7/90 × 7 = 147/630 - Likewise, for the 2nd fraction, since 70 × 9 = 630,
12/70 = 12 × 9/70 × 9 = 108/630 - Add the two like fractions:
147/630 + 108/630 = 147 + 108/630 = 255/630 - 255/630 simplified gives 17/42
- So, 21/90 + 12/70 = 17/42
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