Answer:
-f = 10
Step-by-step explanation:
f(x) = 13 · [tex](1.3)^{x}[/tex], if x = -1
f(-1) = 13 · [tex]1.3^{-1}[/tex]
-1f = 13 · [tex]1.3^{-1}[/tex]
-f = 13 · [tex]\frac{1}{1.3}[/tex]
-f = 1.3 (10) · [tex]\frac{1}{1.3}[/tex]
1.3 cancels
