Subtract 15/18 from 30/42, Solve 30/42

Subtract 15/18 from 30/42

30/42 - 15/18 is -5/42.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 18 is 126

Next, find the equivalent fraction of both fractional numbers with denominator 126
For the 1st fraction, since 42 × 3 = 126,
30/42 = 30 × 3/42 × 3 = 90/126
Likewise, for the 2nd fraction, since 18 × 7 = 126,
15/18 = 15 × 7/18 × 7 = 105/126
Subtract the two like fractions:
90/126 - 105/126 = 90 - 105/126 = -15/126
After reducing the fraction, the answer is -5/42

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