Subtract 90/70 from 21/30
1st number: 21/30, 2nd number: 1 20/70
21/30 - 90/70 is -41/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 70 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 30 × 7 = 210,
21/30 = 21 × 7/30 × 7 = 147/210 - Likewise, for the 2nd fraction, since 70 × 3 = 210,
90/70 = 90 × 3/70 × 3 = 270/210 - Subtract the two like fractions:
147/210 - 270/210 = 147 - 270/210 = -123/210 - After reducing the fraction, the answer is -41/70
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