Question

|x + 1| + |2x - 1| = 0

Answer 1

=>2x-1=0 và x+1=0

=>\(x\in\varnothing\)

Answer 2

|x+1|+|2.x-1|=0

Ta có: |x+1|≥0

          |2.x-1|≥0

\(< =>\left\{{}\begin{matrix}x+1=0\\2.x-1=0\end{matrix}\right.< =>\left\{{}\begin{matrix}x=-1\\x=\dfrac{1}{2}\end{matrix}\right.\)

<=>x∈ϕ