Subtract 72/90 from 15/70
15/70 - 72/90 is -41/70.
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,
15/70 = 15 × 9/70 × 9 = 135/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
72/90 = 72 × 7/90 × 7 = 504/630 - Subtract the two like fractions:
135/630 - 504/630 = 135 - 504/630 = -369/630 - After reducing the fraction, the answer is -41/70
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