Answer:
C. x = 1/2.
Step-by-step explanation:
80 = 1.25(1/2)^(-2x-5)
(0.5)^(-2x-5) = 80 / 1.25 = 64
Taking logs (-2x - 5) ln 0.5 = ln 64
-2x - 5 = ln.4 / ln 0.5 = -6
-2x = -1
x = 1/2.
