Question

Find the area of the circle in simplest polynomial form. A = 3.14r2

(the radius of the circle is 2x+1)

A. 6.28x2 + 3.14
B. 12.56x2 + 3.14>
C. 6.28x2 + 3.14x + 3.14
D. 12.56x2 + 12.56x + 3.14
please help

Answer 1

So I guess the trick here is to square 2x+1 which is the radius.
Can you do that?

Answer 2

A = 3.14r^2
since r = 2x+1

A = 3.14(2x+1)^2
Now all you have to do is simplify this expression.

A=3.14(2x+1)(2x+1)
A=3.14(4x^2 + 2x + 2x + 1)
A=3.14(4x^2 +4x+1)
A=12.56x^2 + 12.56x + 3.14