Subtract 21/70 from 10/80
10/80 - 21/70 is -7/40.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 70 is 560
Next, find the equivalent fraction of both fractional numbers with denominator 560 - For the 1st fraction, since 80 × 7 = 560,
10/80 = 10 × 7/80 × 7 = 70/560 - Likewise, for the 2nd fraction, since 70 × 8 = 560,
21/70 = 21 × 8/70 × 8 = 168/560 - Subtract the two like fractions:
70/560 - 168/560 = 70 - 168/560 = -98/560 - After reducing the fraction, the answer is -7/40
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