Respuesta :

Answer:

Answer below.

Step-by-step explanation:

1. a + 19 | 10 + (a + 9) = a + 19

10 + 9 = 19

a + 19

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2. (C + 2/3) + 1/2 = C + 7/6

2/3 = 4/6

1/2 = 3/6

4/6 + 3/6 = 7/6

C + 7/6

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3. 5 (4n) = 20n

5 x 4n = 20n