Subtract 35/45 from 18/42, Solve 18/42

Subtract 35/45 from 18/42

18/42 - 35/45 is -22/63.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 45 is 630

Next, find the equivalent fraction of both fractional numbers with denominator 630
For the 1st fraction, since 42 × 15 = 630,
18/42 = 18 × 15/42 × 15 = 270/630
Likewise, for the 2nd fraction, since 45 × 14 = 630,
35/45 = 35 × 14/45 × 14 = 490/630
Subtract the two like fractions:
270/630 - 490/630 = 270 - 490/630 = -220/630
After reducing the fraction, the answer is -22/63

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