We can isolate the x terms on one side.
201x=0
Then,
we divide by 201
x=0
So,
x=0
You can check your answer by substituting \(x = 0\) into the original equation:
\(\begin{array}{rcl} \text{LHS} &=& 400 + 0\\ &=& 400\\ \text{RHS} &=& 200x\\ &=& 200(0)\\ &=& 0\\ &\neq& \text{LHS} \end{array}\)
Then \(x= 0\) does not satisfy the equation, and hence your answer is not correct.