Subtract 9/8 from 15/90, Solve 15/90

Subtract 9/8 from 15/90

1^st number: 15/90, 2^nd number: 1 1/8

15/90 - 9/8 is -23/24.

Find the least common denominator or LCM of the two denominators:
LCM of 90 and 8 is 360

Next, find the equivalent fraction of both fractional numbers with denominator 360
For the 1st fraction, since 90 × 4 = 360,
15/90 = 15 × 4/90 × 4 = 60/360
Likewise, for the 2nd fraction, since 8 × 45 = 360,
9/8 = 9 × 45/8 × 45 = 405/360
Subtract the two like fractions:
60/360 - 405/360 = 60 - 405/360 = -345/360
After reducing the fraction, the answer is -23/24

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