Answer:

Step-by-step explanation:
Given









as
∵ 
∵ 
so





Therefore,

Answer:
below
Step-by-step explanation:
f(3)=2
f(20)=0
f(8)=4
f(0)=-1
if f(x)=9 then x=4
if f(x)=4 then x=8
f(x)=0 then x=20
The pie chart is a percent pie chart.
Silicon is 28% of the earth crust = 28/100 = 7/25.