Subtract 70/81 from 15/40
15/40 - 70/81 is -317/648.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 81 is 3240
Next, find the equivalent fraction of both fractional numbers with denominator 3240 - For the 1st fraction, since 40 × 81 = 3240,
15/40 = 15 × 81/40 × 81 = 1215/3240 - Likewise, for the 2nd fraction, since 81 × 40 = 3240,
70/81 = 70 × 40/81 × 40 = 2800/3240 - Subtract the two like fractions:
1215/3240 - 2800/3240 = 1215 - 2800/3240 = -1585/3240 - After reducing the fraction, the answer is -317/648
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