Subtract 7/80 from 28/42, Solve 28/42

Subtract 7/80 from 28/42

28/42 - 7/80 is 139/240.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 80 is 1680

Next, find the equivalent fraction of both fractional numbers with denominator 1680
For the 1st fraction, since 42 × 40 = 1680,
28/42 = 28 × 40/42 × 40 = 1120/1680
Likewise, for the 2nd fraction, since 80 × 21 = 1680,
7/80 = 7 × 21/80 × 21 = 147/1680
Subtract the two like fractions:
1120/1680 - 147/1680 = 1120 - 147/1680 = 973/1680
After reducing the fraction, the answer is 139/240

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