Question

which is the graph of $f(x) = 100(0.7)^x$?

Explanation:

Step1: Find initial value (x=0)

Substitute $x=0$ into $f(x)=100(0.7)^x$.
$f(0)=100(0.7)^0=100\times1=100$
All graphs have $(0,100)$, so check $x=2$.

Step2: Calculate f(2)

Substitute $x=2$ into the function.
$f(2)=100(0.7)^2=100\times0.49=49$

Step3: Match to closest graph

49 is closest to 30 among the given $(2,y)$ points.

Answer:

The top graph with points $(0,100)$ and $(2,30)$