Question

I answered those other questions but need help with this one because I have trouble so can someone answer this for me?

Answer 1

$\bf \begin{array}{ccll} \stackrel{x}{\textit{sprayed times}}&\stackrel{f(x)}{\textit{left termites}}\\ \cline{1-2} 1&12000\left( \frac{1}{4} \right)^1\\\\ 2&12000\left( \frac{1}{4} \right)^2\\\\ 3&12000\left( \frac{1}{4} \right)^3\\\\ x&12000\left( \frac{1}{4} \right)^x\\ \end{array}$