Question

the rational expression $\frac{160x}{100 - x}$ describes the cost, in millions of dollars, to inoculate x percent of the population against a particular strain of flu. complete parts a. through c.
a.evaluate the expression for x = 20, x = 80, and x = 90. describe the meaning of each evaluation in terms of percentage inoculated and cost.
it costs $\square$ million to inoculate 20% of the population.
it costs $\square$ million to inoculate 80% of the population.
it costs $\square$ million to inoculate 90% of the population.
(round to two decimal places as needed.)

Explanation:

Step1: Substitute x = 20

Substitute x = 20 into $\frac{160x}{100 - x}$: $\frac{160\times20}{100 - 20}=\frac{3200}{80}=40$

Step2: Substitute x = 80

Substitute x = 80 into $\frac{160x}{100 - x}$: $\frac{160\times80}{100 - 80}=\frac{12800}{20}=640$

Step3: Substitute x = 90

Substitute x = 90 into $\frac{160x}{100 - x}$: $\frac{160\times90}{100 - 90}=\frac{14400}{10}=1440$

Answer:

It costs $40.00$ million to inoculate 20% of the population.
It costs $640.00$ million to inoculate 80% of the population.
It costs $1440.00$ million to inoculate 90% of the population.