Subtract 21/7 from 7/45, Solve 7/45

Subtract 21/7 from 7/45

1^st number: 7/45, 2^nd number: 3 0/7

7/45 - 21/7 is -128/45.

Find the least common denominator or LCM of the two denominators:
LCM of 45 and 7 is 315

Next, find the equivalent fraction of both fractional numbers with denominator 315
For the 1st fraction, since 45 × 7 = 315,
7/45 = 7 × 7/45 × 7 = 49/315
Likewise, for the 2nd fraction, since 7 × 45 = 315,
21/7 = 21 × 45/7 × 45 = 945/315
Subtract the two like fractions:
49/315 - 945/315 = 49 - 945/315 = -896/315
After reducing the fraction, the answer is -128/45

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