Answer
$m=-\frac{4}{5}$.
Work Step by Step
The given equation is
$\Rightarrow (5m+4)^2=0$
Expand.
$\Rightarrow (5m+4)(5m+4)=0$
Use zero-product property rule.
$\Rightarrow 5m+4=0$ or $5m+4=0$
Solve for $m$.
$\Rightarrow m=-\frac{4}{5}$ or $m=-\frac{4}{5}$
Check:-
$m=-\frac{4}{5}$
$\Rightarrow (5(-\frac{4}{5})+4)^2=0$
$\Rightarrow (-4+4)^2=0$
$\Rightarrow (0)^2=0$
$\Rightarrow 0=0$
True.
Hence, the solution is $m=-\frac{4}{5}$.
