Which of the following represents the value of the series below? (I need someone to double-check the answer I got)

S{28}=sum {k=1}^{28} (9k-4)

S{28}=3542

Answer Choices:

A: S{28}=28{5+248}/{2}

S[28}=3542

B. S{28}=(9(28)-4)+(9(1)-4)

S{28}=253

C. S{28}=28(5+248)

S{28}=7084

D. S{28}=28(248-5)/{2})

S{28}=3402

Hence, A is the answer.

the sum of the areas of the two shaded sectors

step-by-step explanation:

see the attached figure to better understand the problem

we know that

the area of a circle is equal to

where

r is the radius of the circle

in this problem we have

substitute

remember that

subtends the complete circle of area equal to

so

by proportion

find the area of the two shaded sectors