To calculate the value of the phone after two years with a decrease of 22 1/2% each year, we can directly calculate the final value by multiplying the initial value by the decrease factor twice.
The decrease factor is 1 - 22.5/100 = 0.775
So, the value after two years is:
[tex]256.25 \times 0.775 \times 0.775[/tex]
[tex]\approx \$154.16[/tex]
Therefore, the value of the phone after two years is approximately $154.16.