(x + 9)(x + 3)
hope this helps :)
Answer:

Step-by-step explanation:
Given
Area of Sector : Area of Circle = 3 : 5
Required
Determine the central angle
The question implies that

Multiply both sides by 5


Multiply both sides by Area{circle}


Substitute the areas of sector and circle with their respective formulas;


So, we have

Divide both sides by 


Multiply both sides by 360


Divide both sides by 5




Hence, the central angle is 216 degrees
The square root is 6 because 6*6=36
The way I figured this one out was saying that if it takes 2lbs to stretch it to 12 inches and 5lbs to stretch to 18 inches that means that 3 additional pounds = 6 inches. Therefore, each additional pound is 2 inches. We know already that with 2 lbs it was 12 inches in length and we can also say that 2 lbs = 4 inches. So subtract 4 from 12 and you end up with the answer of 8 inches.
The sum of the m numbers divided by m (which is the average) equals n^2. Then, the sum of the m numbers equals mn^2.
The sum of the n numbers divided by n (which is the average) equals m^2. Then, the sum of the n numbers equals nm^2.
The average of m+n numbers which is the sum of the m numbers plus the sum of the n numbers divided by (m+n) equals (mn^2+nm^2)/(m+n). This is mn(n+m)/(m+n). Then the factor (m+n) can be ruled out and the result is mn.