Subtract 35/40 from 8/42, Solve 8/42

Subtract 35/40 from 8/42

8/42 - 35/40 is -115/168.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 40 is 840

Next, find the equivalent fraction of both fractional numbers with denominator 840
For the 1st fraction, since 42 × 20 = 840,
8/42 = 8 × 20/42 × 20 = 160/840
Likewise, for the 2nd fraction, since 40 × 21 = 840,
35/40 = 35 × 21/40 × 21 = 735/840
Subtract the two like fractions:
160/840 - 735/840 = 160 - 735/840 = -575/840
After reducing the fraction, the answer is -115/168

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