A sample of a radioactive isotope had an initial mass of 800 mg in the year 2000 and decays exponentially over time. A measurement in the year 2005 found that the sample's mass had decayed to 190 mg. What would be the expected mass of the sample in the year 2009, to the nearest whole number?

a

step-by-step explanation:

5

10

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25

30

35

40

45

50

55

b because it contains 40% of the possible results from the random list.  

0,1,2,3 v 4,5,6,7,8,9  

4 integers to 6 integers  

40% success vs 60% fail

step-by-step explanation:

x^3-4x^2+3x-2/x^2+1

step-by-step explanation:

factor the numerator and denominator and cancel the common factors