Add 21/40 and 64/90
21/40 + 64/90 is 89/72.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 90 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 40 × 9 = 360,
21/40 = 21 × 9/40 × 9 = 189/360 - Likewise, for the 2nd fraction, since 90 × 4 = 360,
64/90 = 64 × 4/90 × 4 = 256/360 - Add the two like fractions:
189/360 + 256/360 = 189 + 256/360 = 445/360 - 445/360 simplified gives 89/72
- So, 21/40 + 64/90 = 89/72
In mixed form: 117/72
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