Add 21/80 and 72/90
21/80 + 72/90 is 17/16.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 90 is 720
Next, find the equivalent fraction of both fractional numbers with denominator 720 - For the 1st fraction, since 80 × 9 = 720,
21/80 = 21 × 9/80 × 9 = 189/720 - Likewise, for the 2nd fraction, since 90 × 8 = 720,
72/90 = 72 × 8/90 × 8 = 576/720 - Add the two like fractions:
189/720 + 576/720 = 189 + 576/720 = 765/720 - 765/720 simplified gives 17/16
- So, 21/80 + 72/90 = 17/16
In mixed form: 11/16
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