Add 28/21 and 4/25, Solve 1 7/21 + 4/25 as a fraction

Add 28/21 and 4/25

1^st number: 1 7/21, 2^nd number: 4/25

28/21 + 4/25 is 112/75.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 25 is 525

Next, find the equivalent fraction of both fractional numbers with denominator 525
For the 1st fraction, since 21 × 25 = 525,
28/21 = 28 × 25/21 × 25 = 700/525
Likewise, for the 2nd fraction, since 25 × 21 = 525,
4/25 = 4 × 21/25 × 21 = 84/525
Add the two like fractions:
700/525 + 84/525 = 700 + 84/525 = 784/525
784/525 simplified gives 112/75
So, 28/21 + 4/25 = 112/75
In mixed form: 137/75

MathStep (Works offline)

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