Add 42/12 and 75/9, Solve 3 6/12 + 8 3/9 as a fraction

Add 42/12 and 75/9

1^st number: 3 6/12, 2^nd number: 8 3/9

42/12 + 75/9 is 71/6.

Find the least common denominator or LCM of the two denominators:
LCM of 12 and 9 is 36

Next, find the equivalent fraction of both fractional numbers with denominator 36
For the 1st fraction, since 12 × 3 = 36,
42/12 = 42 × 3/12 × 3 = 126/36
Likewise, for the 2nd fraction, since 9 × 4 = 36,
75/9 = 75 × 4/9 × 4 = 300/36
Add the two like fractions:
126/36 + 300/36 = 126 + 300/36 = 426/36
426/36 simplified gives 71/6
So, 42/12 + 75/9 = 71/6
In mixed form: 115/6

MathStep (Works offline)

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