Answer
$r=1$.
Work Step by Step
The given equation is
$\Rightarrow -3r+10=15r-8$
Add $3r+8$ to both sides.
$\Rightarrow -3r+10+3r+8=15r-8+3r+8$
Simplify.
$\Rightarrow 18=18r$
Divide both sides by $18$.
$\Rightarrow \frac{18}{18}=\frac{18r}{18}$
Simplify.
$\Rightarrow 1=r$.
Check:-
$\Rightarrow -3(1)+10=15(1)-8$
$\Rightarrow -3+10=15-8$
$\Rightarrow 7=7$
True.
Hence, the solution is $r=1$.
