Add 90/75 and 81/64, Solve 1 15/75 + 1 17/64 as a fraction

Add 90/75 and 81/64

1^st number: 1 15/75, 2^nd number: 1 17/64

90/75 + 81/64 is 789/320.

Find the least common denominator or LCM of the two denominators:
LCM of 75 and 64 is 4800

Next, find the equivalent fraction of both fractional numbers with denominator 4800
For the 1st fraction, since 75 × 64 = 4800,
90/75 = 90 × 64/75 × 64 = 5760/4800
Likewise, for the 2nd fraction, since 64 × 75 = 4800,
81/64 = 81 × 75/64 × 75 = 6075/4800
Add the two like fractions:
5760/4800 + 6075/4800 = 5760 + 6075/4800 = 11835/4800
11835/4800 simplified gives 789/320
So, 90/75 + 81/64 = 789/320
In mixed form: 2149/320

MathStep (Works offline)

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