Answer:
C
Step-by-step explanation:
Let's check the first condition [y=110, t=0] for all the choices and eliminate:
A)
[tex]y = 110e^{7t} - 80\\y = 110e^{0} - 80\\y=30[/tex]
NO
B)
[tex]y = 110 - 80e^{-5t}\\y = 110 - 80e^{0}\\y=30[/tex]
NO
C)
[tex]y = 30 + 80e^{-2t}\\y = 30 + 80e^{0}\\y=110[/tex]
YES
D)
[tex]y = 110 - 80e^{2t}\\y = 110 - 80e^{0}\\y=30[/tex]
NO
E)
[tex]y = 30 - 80e^{-4t}\\y = 30 - 80e^{0}\\y=-50[/tex]
NO
Note: e^0 = 1
Only C is satisfied. But let's make sure the 2nd condition applies as well.
[tex]y = 30 + 80e^{-2t}\\y = 30 + 80e^{-\infty}\\y=30+\frac{80}{e^{\infty}}\\y>>30[/tex]
Hence, y approaches 30 as t goes to infinity. 2nd condition is satisfied as well.
Answer is C