Subtract 21/70 from 7/72, Solve 7/72

Subtract 21/70 from 7/72

7/72 - 21/70 is -73/360.

Find the least common denominator or LCM of the two denominators:
LCM of 72 and 70 is 2520

Next, find the equivalent fraction of both fractional numbers with denominator 2520
For the 1st fraction, since 72 × 35 = 2520,
7/72 = 7 × 35/72 × 35 = 245/2520
Likewise, for the 2nd fraction, since 70 × 36 = 2520,
21/70 = 21 × 36/70 × 36 = 756/2520
Subtract the two like fractions:
245/2520 - 756/2520 = 245 - 756/2520 = -511/2520
After reducing the fraction, the answer is -73/360

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