Radius and factoring?

Question

I don't know how to to make the pie sign on here so i will just use (pie) for it.

Factor the trinomial to find the radius of the circle.

1. (pie)a^2 - 2(pie)a + (pie)

2. 9(pie)a^2 + 6(pie)a + (pie)

Answer 1

1. Given expression
=pi(a^2-2a+1)
=pi(a-1)^2
Comparing this with the formula of area of a circle pi*r^2,we get r= a-1,where r, is the radius of the circle
2,Given expression
=pi*(9a^2+6a+1)
=pi*{(3a)^2+2*3a*1+(1)^2}
=pi*(3a+1)^2
Comparing this with the formula of area of a circle,which is pi*r^2,where r is the radius of the circle,we get that the radius here is 3a+1 units

Answer 2

Others already answered. I'll give tip to make a pie sign:

copy this sign and paste it to your answer window
∏

Answer 3

1. (pie)a^2 - 2(pie)a + (pie)
= pi(a^2-2a +1) = pi (a-1)^2
So radius must be a-1

2. 9(pie)a^2 + 6(pie)a + (pie)
=pi(9a^2+6a+1) = pi(3a+1)^2
So radius must be 3a+1