Add 40/42 and 30/45
40/42 + 30/45 is 34/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 45 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 42 × 15 = 630,
40/42 = 40 × 15/42 × 15 = 600/630 - Likewise, for the 2nd fraction, since 45 × 14 = 630,
30/45 = 30 × 14/45 × 14 = 420/630 - Add the two like fractions:
600/630 + 420/630 = 600 + 420/630 = 1020/630 - 1020/630 simplified gives 34/21
- So, 40/42 + 30/45 = 34/21
In mixed form: 113/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/42+30/45 40/42+60/45 40/84+30/45 40/42+30/90 40/42+90/45