Subtract 9/10 from 28/42, Solve 28/42

Subtract 9/10 from 28/42

28/42 - 9/10 is -7/30.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 10 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 42 × 5 = 210,
28/42 = 28 × 5/42 × 5 = 140/210
Likewise, for the 2nd fraction, since 10 × 21 = 210,
9/10 = 9 × 21/10 × 21 = 189/210
Subtract the two like fractions:
140/210 - 189/210 = 140 - 189/210 = -49/210
After reducing the fraction, the answer is -7/30

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