Add 90/20 and 21/28
1st number: 4 10/20, 2nd number: 21/28
90/20 + 21/28 is 21/4.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 28 is 140
Next, find the equivalent fraction of both fractional numbers with denominator 140 - For the 1st fraction, since 20 × 7 = 140,
90/20 = 90 × 7/20 × 7 = 630/140 - Likewise, for the 2nd fraction, since 28 × 5 = 140,
21/28 = 21 × 5/28 × 5 = 105/140 - Add the two like fractions:
630/140 + 105/140 = 630 + 105/140 = 735/140 - 735/140 simplified gives 21/4
- So, 90/20 + 21/28 = 21/4
In mixed form: 51/4
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