Subtract 40/70 from 21/63
21/63 - 40/70 is -5/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 63 and 70 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 63 × 10 = 630,
21/63 = 21 × 10/63 × 10 = 210/630 - Likewise, for the 2nd fraction, since 70 × 9 = 630,
40/70 = 40 × 9/70 × 9 = 360/630 - Subtract the two like fractions:
210/630 - 360/630 = 210 - 360/630 = -150/630 - After reducing the fraction, the answer is -5/21
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