Subtract 72/9 from 28/40, Solve 28/40

Subtract 72/9 from 28/40

1^st number: 28/40, 2^nd number: 8 0/9

28/40 - 72/9 is -73/10.

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,
28/40 = 28 × 9/40 × 9 = 252/360
Likewise, for the 2nd fraction, since 9 × 40 = 360,
72/9 = 72 × 40/9 × 40 = 2880/360
Subtract the two like fractions:
252/360 - 2880/360 = 252 - 2880/360 = -2628/360
After reducing the fraction, the answer is -73/10

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