Find $x$ such that $\log_5(x-18)=2$.
That means I want to find $x$ such that $5^2=x-18$, since $\log_b(a)=c$ is equivalent to $b^c=a$. Simplifying the exponential equation, I get $25=x-18$, so I need to add 18 to both sides to isolate $x$. Doing that, I get $x=25+18=43$. 