Respuesta :
The option A and B would be wrong since it was less than the minimum value of the function. To find the cost, you just need to replace the x variable with time after 2005.
If the time is 2025 it will be
x= 2025-2005= 20
y = 15.7x + 459
y = 15.7(20) + 459
y = 314+ 459 = $773.00
If the time is 2030 it will be
x= 2030-2005= 25
y = 15.7x + 459
y = 15.7(25) + 459
y = 392.5+ 459 =$851.50
If the time is 2025 it will be
x= 2025-2005= 20
y = 15.7x + 459
y = 15.7(20) + 459
y = 314+ 459 = $773.00
If the time is 2030 it will be
x= 2030-2005= 25
y = 15.7x + 459
y = 15.7(25) + 459
y = 392.5+ 459 =$851.50