## Elementary Algebra

When we plug in $7$, one of the proposed solutions, into the equation, and simplify using order of operations, the following occurs: $$x(x+2)=7$$$$7(7+2)=7$$$$7(9)=7$$$$63=7$$ Since $63\ne7$, $7$ is not a part of the solution set to the equation, so the statement $\text{must}$ be false.