we have the equation
[tex]9x^2-16y^2=144[/tex]Simplify, divide both sides by 144
[tex]\begin{gathered} \frac{9}{144}x^2-\frac{16}{144}y^2=\frac{144}{144} \\ \\ \frac{x^2}{16}-\frac{y^2}{9}=1 \end{gathered}[/tex]we have
a^2=16
a=4
b^2=9
b=3
using a graphing tool
Find the foci
c^2=a^2+b^2
c^2=16+9
c^2=25
c=5