Start with
[tex]2(x-3)+9=3(x+1)+x[/tex]
Expand both parentheses by multiplying both terms by the number outside:
[tex]2x-6+9 = 3x+3+x[/tex]
Sum like terms:
[tex]2x+3 = 4x+3[/tex]
Simplify the "+3" on both sides:
[tex]2x = 4x[/tex]
Subtract 2x from both sides:
[tex]2x=0[/tex]
Divide both sides by 2:
[tex]x=0[/tex]