Subtract 4/45 from 20/42, Solve 20/42

Subtract 4/45 from 20/42

20/42 - 4/45 is 122/315.

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,
20/42 = 20 × 15/42 × 15 = 300/630
Likewise, for the 2nd fraction, since 45 × 14 = 630,
4/45 = 4 × 14/45 × 14 = 56/630
Subtract the two like fractions:
300/630 - 56/630 = 300 - 56/630 = 244/630
After reducing the fraction, the answer is 122/315

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