Subtract 12/15 from 7/42, Solve 7/42

Subtract 12/15 from 7/42

7/42 - 12/15 is -19/30.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 15 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 42 × 5 = 210,
7/42 = 7 × 5/42 × 5 = 35/210
Likewise, for the 2nd fraction, since 15 × 14 = 210,
12/15 = 12 × 14/15 × 14 = 168/210
Subtract the two like fractions:
35/210 - 168/210 = 35 - 168/210 = -133/210
After reducing the fraction, the answer is -19/30

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