Subtract 7/45 from 42/2, Solve 21 0/2

Subtract 7/45 from 42/2

1^st number: 21 0/2, 2^nd number: 7/45

42/2 - 7/45 is 938/45.

Find the least common denominator or LCM of the two denominators:
LCM of 2 and 45 is 90

Next, find the equivalent fraction of both fractional numbers with denominator 90
For the 1st fraction, since 2 × 45 = 90,
42/2 = 42 × 45/2 × 45 = 1890/90
Likewise, for the 2nd fraction, since 45 × 2 = 90,
7/45 = 7 × 2/45 × 2 = 14/90
Subtract the two like fractions:
1890/90 - 14/90 = 1890 - 14/90 = 1876/90
After reducing the fraction, the answer is 938/45
In mixed form: 2038/45

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad