Add 21/30 and 18/42
21/30 + 18/42 is 79/70.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 42 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 30 × 7 = 210,
21/30 = 21 × 7/30 × 7 = 147/210 - Likewise, for the 2nd fraction, since 42 × 5 = 210,
18/42 = 18 × 5/42 × 5 = 90/210 - Add the two like fractions:
147/210 + 90/210 = 147 + 90/210 = 237/210 - 237/210 simplified gives 79/70
- So, 21/30 + 18/42 = 79/70
In mixed form: 19/70
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