Subtract 21/40 from 12/90
12/90 - 21/40 is -47/120.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 40 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 90 × 4 = 360,
12/90 = 12 × 4/90 × 4 = 48/360 - Likewise, for the 2nd fraction, since 40 × 9 = 360,
21/40 = 21 × 9/40 × 9 = 189/360 - Subtract the two like fractions:
48/360 - 189/360 = 48 - 189/360 = -141/360 - After reducing the fraction, the answer is -47/120
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