Subtract 15/90 from 40/70
40/70 - 15/90 is 17/42.
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,
40/70 = 40 × 9/70 × 9 = 360/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
15/90 = 15 × 7/90 × 7 = 105/630 - Subtract the two like fractions:
360/630 - 105/630 = 360 - 105/630 = 255/630 - After reducing the fraction, the answer is 17/42
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