What are the center and radius of the circle defined by the equation
x2 + y2 - 6x+8y +21= 0 ?

the center is (3, -4) and the radius is = 2

Step-by-step explanation:

for finding the midpoint of any given 2 pair of points simply add the respective x coordinates with other x coordinate and the y coordinate with other y coordinate and divide them by 2

in your question it will be :

(3+1)/2 for the x coordinate of mid point i.e 2

[8+(-4)]/2 for the y coordinate of midpoint i.e 2

so coordinates of mid point of points (3,8) and (1,-4) will be (2,2)

47 - 90 = 43

43 - 180 = x

x = 137