the diameter of a circle has endpoints p(–7, –10) and q(3, 2).
a. find the center of the circle.
b. find the radius. if your answer is not an integer, express it in radical form.
c. write an equation for the circle.

Given:

Two endpoints of a diameter of a circle:

P (-7, -10)
Q (3, 2)

a) To find the center of the circle, find the midpoint of the two points:

midpoint:

(x2 - x1 )/ 2 , (y2 - y1) / 2

x= (2 - (-7))/2 = 4.5
y= (3 - (-10))/2 = 6.5

Therefore, the center of the circle is at C(4.5, 6.5)

 b) To find the radius of the circle, we need to find the distance between the two points and divide by 2.

d = √(y2-y1)^2 + (x2 - x1)^2
d = √(2-(-7))^2 + (3 - (-10))^2
d = 5√10 = diameter
r = d/2 = 5√10 /2 

1.17+3.99a. you combine the terms with a to create 3.99 and the 1.17 stays because it has no like terms or a variable