Step-by-step explanation:
Here are some equations
[tex]{:}\longrightarrow\sf 3x+9=0 [/tex]
[tex]{:}\longrightarrow\sf x+3=0 [/tex]
[tex]{:}\longrightarrow\sf 6x+18=0 [/tex]
[tex]{:}\longrightarrow\sf x^2-9=0 [/tex]
[tex]{:}\longrightarrow\sf x+7=4 [/tex]