Answer:
Divide each side by 3, x=2
Step-by-step explanation:
[tex]\\ \sf{:}\dashrightarrow 3x+1=7[/tex]
[tex]\\ \sf{:}\dashrightarrow 3x=7-1[/tex]
[tex]\\ \sf{:}\dashrightarrow 3x=6[/tex]
[tex]\\ \sf{:}\dashrightarrow x=2[/tex]
