What is 400+x=200x?
400+x=200x400+x−x=200x−xsubtract x400=199x400199=xdivide by 199x=400199exchange sides
We can isolate the x terms on one side.
201x=0
Then,
we divide by 201
x=0
So,
You can check your answer by substituting x=0 into the original equation:
LHS=400+0=400RHS=200x=200(0)=0≠LHS
Then x=0 does not satisfy the equation, and hence your answer is not correct.