Subtract 15/90 from 42/70
42/70 - 15/90 is 13/30.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 90 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 70 × 9 = 630,
42/70 = 42 × 9/70 × 9 = 378/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
15/90 = 15 × 7/90 × 7 = 105/630 - Subtract the two like fractions:
378/630 - 105/630 = 378 - 105/630 = 273/630 - After reducing the fraction, the answer is 13/30
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