[tex]k=150[/tex]
Therefore:
Equation for North America:
[tex]\begin{gathered} N(x)=\frac{150}{\sqrt[]{x}} \\ \end{gathered}[/tex]
--------------------------------
Equation for Europe:
[tex]E(x)=\frac{150}{\sqrt[]{x}}+5[/tex]
-----------------------------
Equation for Asia:
[tex]A(x)=\frac{150}{\sqrt[]{x}}-7[/tex]
