Relax

Respuesta :

Step-by-step explanation:

4 + x + 3x = 4 ( 5x ) - 3 ( x ) - 10

4 + x + 3x = 4 + 5x - 3 + x - 10

x + 3x + 5x + x = 4 + 4 - 3 - 10

10x = 21

10x % 10 = 21 % 10

x = 2,1