Subtract 35/21 from 20/40, Solve 20/40

Subtract 35/21 from 20/40

1^st number: 20/40, 2^nd number: 1 14/21

20/40 - 35/21 is -7/6.

Find the least common denominator or LCM of the two denominators:
LCM of 40 and 21 is 840

Next, find the equivalent fraction of both fractional numbers with denominator 840
For the 1st fraction, since 40 × 21 = 840,
20/40 = 20 × 21/40 × 21 = 420/840
Likewise, for the 2nd fraction, since 21 × 40 = 840,
35/21 = 35 × 40/21 × 40 = 1400/840
Subtract the two like fractions:
420/840 - 1400/840 = 420 - 1400/840 = -980/840
After reducing the fraction, the answer is -7/6

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