Respuesta :

answer:

7

explanation:

7+14=21

21/3=7

Answer:

Step-by-step explanation:

3x = 7 + 14

3x = 21 (7 + 14 = 21)

x = 7 (divide 3 from both sides) (3x / 3 = x and 21 / 3 = 7)