Subtract 9/42 from 7/20, Solve 7/20

Subtract 9/42 from 7/20

7/20 - 9/42 is 19/140.

Find the least common denominator or LCM of the two denominators:
LCM of 20 and 42 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 20 × 21 = 420,
7/20 = 7 × 21/20 × 21 = 147/420
Likewise, for the 2nd fraction, since 42 × 10 = 420,
9/42 = 9 × 10/42 × 10 = 90/420
Subtract the two like fractions:
147/420 - 90/420 = 147 - 90/420 = 57/420
After reducing the fraction, the answer is 19/140

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