Question

с в степени 2 дробь 9 при с=3√5

Answer 1

$\displaystyle \tt \frac{c^2}9, \quad c=3\sqrt{5}\\\\\frac{(3\sqrt5)^2}9=\frac{3^2\cdot5}{9}=\frac{9\cdot5}{9}=\boxed{5}$