Subtract 8/30 from 21/42, Solve 21/42

Subtract 8/30 from 21/42

21/42 - 8/30 is 7/30.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 30 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 30 × 7 = 210,
8/30 = 8 × 7/30 × 7 = 56/210
Subtract the two like fractions:
105/210 - 56/210 = 105 - 56/210 = 49/210
After reducing the fraction, the answer is 7/30

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