Subtract 21/90 from 7/70
7/70 - 21/90 is -2/15.
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,
7/70 = 7 × 9/70 × 9 = 63/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
21/90 = 21 × 7/90 × 7 = 147/630 - Subtract the two like fractions:
63/630 - 147/630 = 63 - 147/630 = -84/630 - After reducing the fraction, the answer is -2/15
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