Subtract 21/42 from 70/50, Solve 1 20/50

Subtract 21/42 from 70/50

1^st number: 1 20/50, 2^nd number: 21/42

70/50 - 21/42 is 9/10.

Find the least common denominator or LCM of the two denominators:
LCM of 50 and 42 is 1050

Next, find the equivalent fraction of both fractional numbers with denominator 1050
For the 1st fraction, since 50 × 21 = 1050,
70/50 = 70 × 21/50 × 21 = 1470/1050
Likewise, for the 2nd fraction, since 42 × 25 = 1050,
21/42 = 21 × 25/42 × 25 = 525/1050
Subtract the two like fractions:
1470/1050 - 525/1050 = 1470 - 525/1050 = 945/1050
After reducing the fraction, the answer is 9/10

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