Subtract 42/40 from 8/84, Solve 8/84

Subtract 42/40 from 8/84

1^st number: 8/84, 2^nd number: 1 2/40

8/84 - 42/40 is -401/420.

Find the least common denominator or LCM of the two denominators:
LCM of 84 and 40 is 840

Next, find the equivalent fraction of both fractional numbers with denominator 840
For the 1st fraction, since 84 × 10 = 840,
8/84 = 8 × 10/84 × 10 = 80/840
Likewise, for the 2nd fraction, since 40 × 21 = 840,
42/40 = 42 × 21/40 × 21 = 882/840
Subtract the two like fractions:
80/840 - 882/840 = 80 - 882/840 = -802/840
After reducing the fraction, the answer is -401/420

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