Subtract 2/80 from 20/21, Solve 20/21

Subtract 2/80 from 20/21

20/21 - 2/80 is 779/840.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 80 is 1680

Next, find the equivalent fraction of both fractional numbers with denominator 1680
For the 1st fraction, since 21 × 80 = 1680,
20/21 = 20 × 80/21 × 80 = 1600/1680
Likewise, for the 2nd fraction, since 80 × 21 = 1680,
2/80 = 2 × 21/80 × 21 = 42/1680
Subtract the two like fractions:
1600/1680 - 42/1680 = 1600 - 42/1680 = 1558/1680
After reducing the fraction, the answer is 779/840

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