Subtract 21/7 from 50/90, Solve 50/90

Subtract 21/7 from 50/90

1^st number: 50/90, 2^nd number: 3 0/7

50/90 - 21/7 is -22/9.

Find the least common denominator or LCM of the two denominators:
LCM of 90 and 7 is 630

Next, find the equivalent fraction of both fractional numbers with denominator 630
For the 1st fraction, since 90 × 7 = 630,
50/90 = 50 × 7/90 × 7 = 350/630
Likewise, for the 2nd fraction, since 7 × 90 = 630,
21/7 = 21 × 90/7 × 90 = 1890/630
Subtract the two like fractions:
350/630 - 1890/630 = 350 - 1890/630 = -1540/630
After reducing the fraction, the answer is -22/9

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