Question

6x+3=4x+9 can you guys explain this for me

Answer 1

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

Answer 2

$6x+3=4x+9 \\ 2x=6\\ x=3$