Subtract 70/45 from 21/28, Solve 21/28

Subtract 70/45 from 21/28

1^st number: 21/28, 2^nd number: 1 25/45

21/28 - 70/45 is -29/36.

Find the least common denominator or LCM of the two denominators:
LCM of 28 and 45 is 1260

Next, find the equivalent fraction of both fractional numbers with denominator 1260
For the 1st fraction, since 28 × 45 = 1260,
21/28 = 21 × 45/28 × 45 = 945/1260
Likewise, for the 2nd fraction, since 45 × 28 = 1260,
70/45 = 70 × 28/45 × 28 = 1960/1260
Subtract the two like fractions:
945/1260 - 1960/1260 = 945 - 1960/1260 = -1015/1260
After reducing the fraction, the answer is -29/36

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