Respuesta :

Answer:

x=-6

Step-by-step explanation:

Answer:

X = -6

Step-by-step explanation:

3x+9 = 5x+21

3x-5x=21-9

-2x=12

-X= 12/2

-x=6

Multiply both sides by (-1)

-x*-1 = 6*-1

X = -6