Subtract 1/21 from 70/40, Solve 1 30/40

Subtract 1/21 from 70/40

1^st number: 1 30/40, 2^nd number: 1/21

70/40 - 1/21 is 143/84.

Find the least common denominator or LCM of the two denominators:
LCM of 40 and 21 is 840

Next, find the equivalent fraction of both fractional numbers with denominator 840
For the 1st fraction, since 40 × 21 = 840,
70/40 = 70 × 21/40 × 21 = 1470/840
Likewise, for the 2nd fraction, since 21 × 40 = 840,
1/21 = 1 × 40/21 × 40 = 40/840
Subtract the two like fractions:
1470/840 - 40/840 = 1470 - 40/840 = 1430/840
After reducing the fraction, the answer is 143/84
In mixed form: 159/84

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