Subtract 40/42 from 7/20
7/20 - 40/42 is -253/420.
Steps for subtracting fractions
- 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,
40/42 = 40 × 10/42 × 10 = 400/420 - Subtract the two like fractions:
147/420 - 400/420 = 147 - 400/420 = -253/420
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