Add 21/42 and 15/70
21/42 + 15/70 is 5/7.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 70 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 42 × 5 = 210,
21/42 = 21 × 5/42 × 5 = 105/210 - Likewise, for the 2nd fraction, since 70 × 3 = 210,
15/70 = 15 × 3/70 × 3 = 45/210 - Add the two like fractions:
105/210 + 45/210 = 105 + 45/210 = 150/210 - 150/210 simplified gives 5/7
- So, 21/42 + 15/70 = 5/7
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