Solutions by everydaycalculation.com

2142 + 2130 is 65.

- Find the least common denominator or LCM of the two denominators:

LCM of 42 and 30 is**210**

Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 42 × 5 = 210,

2142 = 21 × 542 × 5 = 105210 - Likewise, for the 2nd fraction, since 30 × 7 = 210,

2130 = 21 × 730 × 7 = 147210 - Add the two like fractions:

105210 + 147210 = 105 + 147210 = 252210 - 252/210 simplified gives 65
- So, 21/42 + 21/30 = 6/5

In mixed form: 115

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