Subtract 21/90 from 1/70
1/70 - 21/90 is -23/105.
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,
1/70 = 1 × 9/70 × 9 = 9/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
21/90 = 21 × 7/90 × 7 = 147/630 - Subtract the two like fractions:
9/630 - 147/630 = 9 - 147/630 = -138/630 - After reducing the fraction, the answer is -23/105
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