You multiply both the sides and the top and add them
Radii is defined as the line joining the centre of the circle to a point on the circumference
as there are infinite points on a circle
therefore there are infinite number of radii and hence there is no fixed number.
Answer: 
<u>Add 13 to both sides</u>
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105 = 7. (1 - 2^n) / 1-2
105*-1 = 7 (1 - 2^n)
1 - 2^n = -105/7 = - 15
2^n = 16
n = 4 answer
The water is flowing into the pool at 1.5 gallons per minute and it would take 20 minutes to be filled.
<h3>
What is an Equation</h3>
An equation is used to show the relationship between two or more numbers and variables.
The pool holds 30 gallons of water. After 5 minutes, the pool is about one fourth full. Hence:
Time to full the pool = 5 minutes * 4 = 20 minutes
Rate of water flow = 30 gallons/20 minutes = 1.5 gallons per minute
The water is flowing into the pool at 1.5 gallons per minute and it would take 20 minutes to be filled.
Find out more on Equation at: brainly.com/question/13763238