Subtract 12/7 from 28/30, Solve 28/30

Subtract 12/7 from 28/30

1^st number: 28/30, 2^nd number: 1 5/7

28/30 - 12/7 is -82/105.

Find the least common denominator or LCM of the two denominators:
LCM of 30 and 7 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 30 × 7 = 210,
28/30 = 28 × 7/30 × 7 = 196/210
Likewise, for the 2nd fraction, since 7 × 30 = 210,
12/7 = 12 × 30/7 × 30 = 360/210
Subtract the two like fractions:
196/210 - 360/210 = 196 - 360/210 = -164/210
After reducing the fraction, the answer is -82/105

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