Answer
$r=0$ and $r=10$.
Work Step by Step
The given equation is
$\Rightarrow r(r-10)=0$
Use zero-product property rule.
$\Rightarrow r=0$ or $r-10=0$
Solve for $r$.
$\Rightarrow r=0$ or $r=10$
Check:-
$r=0$
$\Rightarrow 0(0-10)=0$
$\Rightarrow 0(-10)=0$
$\Rightarrow 0=0$
True.
Check:-
$r=10$
$\Rightarrow 10(10-10)=0$
$\Rightarrow 10(0)=0$
$\Rightarrow 0=0$
True.
Hence, the solutions are $r=0$ and $r=10$.
