Respuesta :

mhanifa

Answer:

  • a) f(x) = - 20x + 450
  • b) 30 pages left to read

Step-by-step explanation:

Given sequence:

  • 430, 410, 390, ...

The first term is 430 and the common difference is - 20.

a)

Required function is:

  • f(x) = 430 - 20Ix - 1) = 430 - 20x + 20 = 450 - 20x

or

  • f(x) = -20x + 450

b)

Find the number of pages left after 21 days:

  • f(21) = 450 - 20*21 = 450 - 420 = 30