## Elementary Algebra

Solving the equation by squaring each side of the equation and simplifying, we obtain: $\sqrt {x+1}=-2$ $(\sqrt {x+1})^{2}=(-2)^{2}$ $x+1=4$ $x=4-1$ $x=3$ As $\sqrt {3+1}\ne-2$, $3$ is not a solution to this equation. Therefore, the statement of the question is true.