Given,

Suppose you purchase an iPhone X for $720 when it initially launched. The resale value decreases 3.08% each month since launch.

So, the price of the iPhone X after 1 month \(\displaystyle={\left({\frac{{{100}-{3.08}}}{{{100}}}}\right)}\times{720}\)

\(\displaystyle={0.9692}\times{720}\)

Again, the price of the iPhone X after 2 months \(\displaystyle={\left({\frac{{{100}-{3.08}}}{{{100}}}}\right)}\times{0.9692}\times{720}\)

\(\displaystyle={0.9692}^{{2}}\times{720}\)

Therefore, the price of the iPhone X after t month \(\displaystyle={0.9692}^{{t}}\times{720}\)

\(\displaystyle={0.97}^{{t}}\times{720}\)

ANSWER

\(\displaystyle{P}{\left({t}\right)}={0.97}^{{t}}\times{720}\)

Suppose you purchase an iPhone X for $720 when it initially launched. The resale value decreases 3.08% each month since launch.

So, the price of the iPhone X after 1 month \(\displaystyle={\left({\frac{{{100}-{3.08}}}{{{100}}}}\right)}\times{720}\)

\(\displaystyle={0.9692}\times{720}\)

Again, the price of the iPhone X after 2 months \(\displaystyle={\left({\frac{{{100}-{3.08}}}{{{100}}}}\right)}\times{0.9692}\times{720}\)

\(\displaystyle={0.9692}^{{2}}\times{720}\)

Therefore, the price of the iPhone X after t month \(\displaystyle={0.9692}^{{t}}\times{720}\)

\(\displaystyle={0.97}^{{t}}\times{720}\)

ANSWER

\(\displaystyle{P}{\left({t}\right)}={0.97}^{{t}}\times{720}\)