+845 
ONLY question c please
for centre and radius my answer is (3,-2) and r = 5
im not sure what the question means by postive y axis and the method to get to r
+129852 x^2 - 6x + y^2 + 4y = 12 complete the square on x, y
x^2 - 6x + 9 + y^2 + 4y + 4 = 12 + 9 + 4
(x - 3)^2 + (y + 2)^2 = 25
Since R lies on the positive y axis, it must have the coordinates (0, a) where a is positive
So......x = 0 and we have
(0 - 3)^2 + ( y + 2)^2 = 25
9 + ( y + 2)^2 = 25 rearrange as
(y + 2)^2 = 16 take the positive root
y + 2 = 4
y = 2
So....R = (0, 2)
Here's the graph, YEEEEEET : https://www.desmos.com/calculator/j8cvgj36zi
