Respuesta :

jmtorres3423
Start by distributing the negative sign:\
-9-12+3x
Simplify:
-21+3x
SATnoSTOP
First, distribute the -1

-9-12+3x

Then subtract the -9 and -12

-21 + 3x

Add 21 to both sides*

21 = 3x

Divide

x = 7

*I would assume that 0= -9-(12-3x) as it is not mentioned in the description