-transpose and change the signs
-divide them by 3, so that it will remove the constant "3" in x.
-cancel the constant"3", so it will remain the x, then do the same in the other side.
-so here you go. the result (≡^∇^≡)
hope you understand it. Actually, I'm not good in mathematics, so I try to solve your math problem to test also my skills and knowledge in math hihi