Respuesta :

Answer:

21

Step-by-step explanation:

1) Simplify 1 + 2 to 3.

1 + 2 + 3 ×  ( 3 + 3 )

2) Simplify 3 + 3 to 6.

1 + 2 + 3 × 6

3) Simplify 3 × 6 to 18.

1 + 2 + 18

4) Simplify 1 + 2 to 3.

3 + 18

5) Simplify.

21