Subtract 12/36 from 90/70, Solve 1 20/70

Subtract 12/36 from 90/70

1^st number: 1 20/70, 2^nd number: 12/36

90/70 - 12/36 is 20/21.

Find the least common denominator or LCM of the two denominators:
LCM of 70 and 36 is 1260

Next, find the equivalent fraction of both fractional numbers with denominator 1260
For the 1st fraction, since 70 × 18 = 1260,
90/70 = 90 × 18/70 × 18 = 1620/1260
Likewise, for the 2nd fraction, since 36 × 35 = 1260,
12/36 = 12 × 35/36 × 35 = 420/1260
Subtract the two like fractions:
1620/1260 - 420/1260 = 1620 - 420/1260 = 1200/1260
After reducing the fraction, the answer is 20/21

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