Thinking Mathematically (6th Edition)

$\dfrac{\sqrt{35}}{7}$
Rationalize the denominator by multiplying $7$ to both the numerator and denominator inside the radical sign to find: $=\sqrt{\dfrac{5(7)}{7(7)}} \\=\sqrt{\dfrac{35}{7^2}} \\=\dfrac{\sqrt{35}}{7}$