Subtract 90/72 from 70/42, Solve 1 28/42

Subtract 90/72 from 70/42

1^st number: 1 28/42, 2^nd number: 1 18/72

70/42 - 90/72 is 5/12.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 72 is 504

Next, find the equivalent fraction of both fractional numbers with denominator 504
For the 1st fraction, since 42 × 12 = 504,
70/42 = 70 × 12/42 × 12 = 840/504
Likewise, for the 2nd fraction, since 72 × 7 = 504,
90/72 = 90 × 7/72 × 7 = 630/504
Subtract the two like fractions:
840/504 - 630/504 = 840 - 630/504 = 210/504
After reducing the fraction, the answer is 5/12

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