Add 12/21 and 21/30
12/21 + 21/30 is 89/70.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 30 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 21 × 10 = 210,
12/21 = 12 × 10/21 × 10 = 120/210 - Likewise, for the 2nd fraction, since 30 × 7 = 210,
21/30 = 21 × 7/30 × 7 = 147/210 - Add the two like fractions:
120/210 + 147/210 = 120 + 147/210 = 267/210 - 267/210 simplified gives 89/70
- So, 12/21 + 21/30 = 89/70
In mixed form: 119/70
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