c ll en 15 Write the standard equation of each circle a b c
     c. ll en 15. Write the standard equation of each circle a. b. c.  
  
  Solution
15.
Equation of circle is (x-a)^2 + (y-b)^2 = r^2, where a,b is where center of circle is with radius of r
a.
 r = 5, and center is at origin(0,0)
 (x-0)^2 +(y-0)^2 = 5^2
 x^2+y^2 = 25
 b.
 r = 5, and center is at (4,3)
 (x-4)^2 +(y-3)^2 = 5^2 = 25
c.
 r = 3, and center is at (5,4)
 (x-5)^2 + (y-4)^2 = 3^2 = 9

