Subtract 81/7 from 20/45, Solve 20/45

Subtract 81/7 from 20/45

1^st number: 20/45, 2^nd number: 11 4/7

20/45 - 81/7 is -701/63.

Find the least common denominator or LCM of the two denominators:
LCM of 45 and 7 is 315

Next, find the equivalent fraction of both fractional numbers with denominator 315
For the 1st fraction, since 45 × 7 = 315,
20/45 = 20 × 7/45 × 7 = 140/315
Likewise, for the 2nd fraction, since 7 × 45 = 315,
81/7 = 81 × 45/7 × 45 = 3645/315
Subtract the two like fractions:
140/315 - 3645/315 = 140 - 3645/315 = -3505/315
After reducing the fraction, the answer is -701/63

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