If f(x) is the total number of bacteria present in a sample after x hours , which of the following statements best describes the meaning of f(2)=12 a. the total number of bacteria present in a sample after 12 hours is 2. b. the total number of bacteria present in the sample after 6 hours is 12. c. the total number of bacteria present in the sample after 2 hours is 12. d. the total number of bacteria present in the sample after 6 hours is 12.

 C. The total number of bacteria present in the sample after 2 hours is 12.

Step-by-step explanation:

The given statement :  f(x) is the total number of bacteria present in a sample after x hours.

It means the independent quantity = Number of hours

i.e. The independent variable in the given situation = x

Also, the dependent quantity =  Total number of bacteria

i.e. The dependent variable in the given situation = f(x)

Therefore, the meaning of "f(2)=12" is the total number of bacteris present in sample is 12 after 2 hours.

area of part 1:

a1=base*height/2=(8+2)*(8-2-2-1)/2=10*3/2=15 ft^2

area of part 2:

a2=length*width=(8+2)*1=10 ft2

area of part 3:

a3=length*width=8*2=16 ft2

total shaded area : a1+a2+a3=41 ft2

total area of the reactangle : a=16*8=128 ft2

total area of the nonshaded region : 128-41=87 ft2