Subtract 50/42 from 21/36, Solve 21/36

Subtract 50/42 from 21/36

1^st number: 21/36, 2^nd number: 1 8/42

21/36 - 50/42 is -17/28.

Find the least common denominator or LCM of the two denominators:
LCM of 36 and 42 is 252

Next, find the equivalent fraction of both fractional numbers with denominator 252
For the 1st fraction, since 36 × 7 = 252,
21/36 = 21 × 7/36 × 7 = 147/252
Likewise, for the 2nd fraction, since 42 × 6 = 252,
50/42 = 50 × 6/42 × 6 = 300/252
Subtract the two like fractions:
147/252 - 300/252 = 147 - 300/252 = -153/252
After reducing the fraction, the answer is -17/28

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