Add 42/72 and 18/21
42/72 + 18/21 is 121/84.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 21 is 504
Next, find the equivalent fraction of both fractional numbers with denominator 504 - For the 1st fraction, since 72 × 7 = 504,
42/72 = 42 × 7/72 × 7 = 294/504 - Likewise, for the 2nd fraction, since 21 × 24 = 504,
18/21 = 18 × 24/21 × 24 = 432/504 - Add the two like fractions:
294/504 + 432/504 = 294 + 432/504 = 726/504 - 726/504 simplified gives 121/84
- So, 42/72 + 18/21 = 121/84
In mixed form: 137/84
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