Subtract 12/45 from 4/42, Solve 4/42

Subtract 12/45 from 4/42

4/42 - 12/45 is -6/35.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 45 is 630

Next, find the equivalent fraction of both fractional numbers with denominator 630
For the 1st fraction, since 42 × 15 = 630,
4/42 = 4 × 15/42 × 15 = 60/630
Likewise, for the 2nd fraction, since 45 × 14 = 630,
12/45 = 12 × 14/45 × 14 = 168/630
Subtract the two like fractions:
60/630 - 168/630 = 60 - 168/630 = -108/630
After reducing the fraction, the answer is -6/35

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