A Galapagos cactus finch population increases by half every decade. The number of finches is modeled by the expression 45 • 1.5d, where d is the number of decades after the population was measured. Evaluate the expression to find the number of finches for d = –2.
(1 point)
Responses
20
68
900
4,556
To evaluate the expression for d = –2, substitute –2 for d in the expression 45 • 1.5d:
45 • 1.5(-2)
= 45 • (-3)
= -135
Therefore, the number of finches for d = –2 is -135. However, since a population cannot have a negative number of individuals, this result is not valid. Hence, none of the given options (20, 68, 900, and 4,556) is the correct answer.