Respuesta :

jaleena1215

Answer:

A

Step-by-step explanation:

Because the only step is to subtract 9 from both sides and then you get x=12

:)

BORN2WIN

Answer:

there is no one step equation becuz

x+9 = 21

take 9 to the other side becos both are same variables then

21-9 = x

hence x= 12

next x=11 question can't be answered becuz this is not a complete question

2x+9 = 21

21-9 = 2x

12=2x

x=

12

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2

hwnce 12/2 = 6 therefore x= 6