Add 20/21 and 42/27, Solve 20/21 + 1 15/27 as a fraction

Add 20/21 and 42/27

1^st number: 20/21, 2^nd number: 1 15/27

20/21 + 42/27 is 158/63.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 27 is 189

Next, find the equivalent fraction of both fractional numbers with denominator 189
For the 1st fraction, since 21 × 9 = 189,
20/21 = 20 × 9/21 × 9 = 180/189
Likewise, for the 2nd fraction, since 27 × 7 = 189,
42/27 = 42 × 7/27 × 7 = 294/189
Add the two like fractions:
180/189 + 294/189 = 180 + 294/189 = 474/189
474/189 simplified gives 158/63
So, 20/21 + 42/27 = 158/63
In mixed form: 232/63

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