Subtract 15/90 from 10/70
10/70 - 15/90 is -1/42.
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,
10/70 = 10 × 9/70 × 9 = 90/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
15/90 = 15 × 7/90 × 7 = 105/630 - Subtract the two like fractions:
90/630 - 105/630 = 90 - 105/630 = -15/630 - After reducing the fraction, the answer is -1/42
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