In a village, the cases of a particular infectious
disease have been exponentially decreasing at
a rate of 90% per year since the people started
receiving the vaccine. If there were 100 cases
in the village to start with, predict the number
of cases after 3 years.
First, complete the equation:
Remaining Amount = 100(1 -0.90)3
Now solve.
Remaining Amount = [ ? ] cases

  0

Step-by-step explanation:

We assume that "complete the equation" means evaluate the difference:

  remaining amount = 100(0.1^3)

  remaining amount = 100(0.001) = 0.1 ≈ 0

Something like "cases" is usually expected to be an integer, so we expect the solution will need to be rounded to the nearest integer. The calculated value of 0.1 is nearest to the integer 0.

The predicted number of cases after 3 years is 0.

your answer would be 10x - 1

hello from mrbilldoesmath!

answer:

x - 3

discussion:

x^2 - 9 = (x-3) (x+3)   so

(x^2-9)/ (x + 3) = x-3

you,

mrb