SOLUTION:
To get the total time in which the ball is in the air, we just have to solve the equation for the roots, the difference between the roots is the total air-time.
The equation is;
[tex]\begin{gathered} -13x^2+65x=0 \\ \\ 65x=13x^2 \\ \\ divide\text{ }through\text{ }by\text{ }x \\ \\ 65=13x \\ \\ x=5\text{ }or\text{ }x=0 \end{gathered}[/tex]
Thus, the total time spent in the air is ;
[tex]5[/tex]
