Answer:
Hey there!
3x-9=12
3x=21
x=7
Let me know if this helps :)
Step-by-step explanation:
[tex]3x - 9 = 12 \\ collect \: like \: terms \\ 3x = 12 + 9 \\ 3x = 21 \\ divide \: both \: sides \: by \: 3[/tex]
[tex] \frac{3x}{3} = \frac{21}{7} \\ x = 7[/tex]
