Add 21/28 and 45/80
21/28 + 45/80 is 21/16.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 80 is 560
Next, find the equivalent fraction of both fractional numbers with denominator 560 - For the 1st fraction, since 28 × 20 = 560,
21/28 = 21 × 20/28 × 20 = 420/560 - Likewise, for the 2nd fraction, since 80 × 7 = 560,
45/80 = 45 × 7/80 × 7 = 315/560 - Add the two like fractions:
420/560 + 315/560 = 420 + 315/560 = 735/560 - 735/560 simplified gives 21/16
- So, 21/28 + 45/80 = 21/16
In mixed form: 15/16
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