Answer :

[tex]6x+3=4x+9 \\ 2x=6\\ x=3[/tex]
We have such equation
6x+3=4x+9             /-4x      subtract 4x both sides
6x-4x+3=4x-4x+9
2x+3=9            /-3     subtract 3 both sides   
2x=6               /:2      divide both sides by 2
x=3 - its result