Add 70/80 and 30/42
70/80 + 30/42 is 89/56.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 42 is 1680
Next, find the equivalent fraction of both fractional numbers with denominator 1680 - For the 1st fraction, since 80 × 21 = 1680,
70/80 = 70 × 21/80 × 21 = 1470/1680 - Likewise, for the 2nd fraction, since 42 × 40 = 1680,
30/42 = 30 × 40/42 × 40 = 1200/1680 - Add the two like fractions:
1470/1680 + 1200/1680 = 1470 + 1200/1680 = 2670/1680 - 2670/1680 simplified gives 89/56
- So, 70/80 + 30/42 = 89/56
In mixed form: 133/56
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/80+60/42 70/80+30/84 70/80+90/42