A laptop computer is purchased four 4400 dollars. Each year, it's value is 75% of it's value the year before. After how many years will the laptop computer be worth 900 dollars or less? Write the smallest possible whole number answer

We will determine the time it will take to be worth $900 or less as follows:
[tex]\begin{gathered} 900=4400(0.75)^x\Rightarrow\frac{9}{44}=(0.75)^x \\ \\ \Rightarrow ln(\frac{9}{44})=xln(0.75)\Rightarrow x=\frac{ln(9/44)}{ln(0.75)} \\ \\ \Rightarrow x=5.516384956...\Rightarrow x\approx6 \end{gathered}[/tex]So, it will be approximately 6 years until the laptop is worth $900 or less.