Subtract 70/9 from 72/21
1st number: 3 9/21, 2nd number: 7 7/9
72/21 - 70/9 is -274/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 9 is 63
Next, find the equivalent fraction of both fractional numbers with denominator 63 - For the 1st fraction, since 21 × 3 = 63,
72/21 = 72 × 3/21 × 3 = 216/63 - Likewise, for the 2nd fraction, since 9 × 7 = 63,
70/9 = 70 × 7/9 × 7 = 490/63 - Subtract the two like fractions:
216/63 - 490/63 = 216 - 490/63 = -274/63
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