To evaluate the given expression, we first compute the values of the infinite geometric series α and β.
Step 1: Calculate α
The series for α is an infinite geometric progression with first term a1=41 and common ratio r1=21:
α=41+81+161+…∞=1−2141=2141=21
Step 2: Calculate β
The series for β is also an infinite geometric progression with first term a2=31 and common ratio r2=31:
β=31+91+271+…∞=1−3131=3231=21
Step 3: Evaluate the logarithmic expression
We are required to find the value of:
E=(0.2)log5(α)+(0.04)log5(β)
Let's evaluate the first term:
(0.2)log5(α)=(5−1)log51/2(21)
Using the property logbk(x)=k1logb(x):
log51/2(21)=2log5(21)
Substituting this back into the first term:
(0.2)log5(α)=5−(2log5(21))=5log5((21)−2)=5log5(4)=4
Now, let's evaluate the second term:
(0.04)log5(β)=(5−2)log5(21)=5−2log5(21)=5log5((21)−2)=5log5(4)=4
Step 4: Sum the termsE=4+4=8
Thus, the value of the given expression is 8, which corresponds to Option C.