## Intermediate Algebra (6th Edition)

$\text{ approximately } 27 \text{ } mph$
Substituting $r=300,$ in the given function, $V(r)=\sqrt{2.5r} ,$ results to \begin{array}{l}\require{cancel} V(r)=\sqrt{2.5(300)} \\ V(r)=\sqrt{750} .\end{array} Using the properties of radicals, the equation above is equivalent to \begin{array}{l}\require{cancel} V(r)=\sqrt{25\cdot30} \\ V(r)=\sqrt{5^2\cdot30} \\ V(r)=5\sqrt{30} \\ V(r)\approx27 .\end{array} Hence, the maximum safe velocity, $V,$ is $\text{ approximately } 27 \text{ } mph .$