Add 21/40 and 70/80
21/40 + 70/80 is 7/5.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 80 is 80
Next, find the equivalent fraction of both fractional numbers with denominator 80 - For the 1st fraction, since 40 × 2 = 80,
21/40 = 21 × 2/40 × 2 = 42/80 - Likewise, for the 2nd fraction, since 80 × 1 = 80,
70/80 = 70 × 1/80 × 1 = 70/80 - Add the two like fractions:
42/80 + 70/80 = 42 + 70/80 = 112/80 - 112/80 simplified gives 7/5
- So, 21/40 + 70/80 = 7/5
In mixed form: 12/5
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