# Show that x = −3 is a solution of

Question:

Show that $x=-3$ is a solution of $x^{2}+6 x+9=0$.

Solution:

Given that the equation $x^{2}+6 x+9=0$

$x^{2}+3 x+3 x+9=0$

$x(x+3)+3(x+3)=0$

$(x+3)(x+3)=0$

$(x+3)^{2}=0$

Square root both side, we get

$(x+3)=0$

$x=-3$

Therefore, $x=-3$ is the solution of given equation.

Hence, proved.