Answer:
Step-by-step explanation:
[tex]D=\frac{k}{\sqrt{m}}\\\\64=\frac{k}{\sqrt{9}}\\\\64=\frac{k}{3}\\\\ 64*3=k\\\\k=192\\a)D=\frac{192}{\sqrt{4}}\\\\=\frac{192}{2}\\\\D=96\\\\b)32=\frac{192}{\sqrt{m}}\\\\ 32*\sqrt{m}=192\\\\\sqrt{m}=\frac{192}{32}=6\\\\m=36[/tex]