Subtract 20/40 from 12/30, Solve 12/30

Subtract 20/40 from 12/30

12/30 - 20/40 is -1/10.

Find the least common denominator or LCM of the two denominators:
LCM of 30 and 40 is 120

Next, find the equivalent fraction of both fractional numbers with denominator 120
For the 1st fraction, since 30 × 4 = 120,
12/30 = 12 × 4/30 × 4 = 48/120
Likewise, for the 2nd fraction, since 40 × 3 = 120,
20/40 = 20 × 3/40 × 3 = 60/120
Subtract the two like fractions:
48/120 - 60/120 = 48 - 60/120 = -12/120
After reducing the fraction, the answer is -1/10

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