Subtract 21/9 from 27/40, Solve 27/40

Subtract 21/9 from 27/40

1^st number: 27/40, 2^nd number: 2 3/9

27/40 - 21/9 is -199/120.

Find the least common denominator or LCM of the two denominators:
LCM of 40 and 9 is 360

Next, find the equivalent fraction of both fractional numbers with denominator 360
For the 1st fraction, since 40 × 9 = 360,
27/40 = 27 × 9/40 × 9 = 243/360
Likewise, for the 2nd fraction, since 9 × 40 = 360,
21/9 = 21 × 40/9 × 40 = 840/360
Subtract the two like fractions:
243/360 - 840/360 = 243 - 840/360 = -597/360
After reducing the fraction, the answer is -199/120

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