Subtract 3/4 from 21/70
21/70 - 3/4 is -9/20.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 4 is 140
Next, find the equivalent fraction of both fractional numbers with denominator 140 - For the 1st fraction, since 70 × 2 = 140,
21/70 = 21 × 2/70 × 2 = 42/140 - Likewise, for the 2nd fraction, since 4 × 35 = 140,
3/4 = 3 × 35/4 × 35 = 105/140 - Subtract the two like fractions:
42/140 - 105/140 = 42 - 105/140 = -63/140 - After reducing the fraction, the answer is -9/20
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