Step-by-step explanation:
General equation of the circle with center (h,k) and radius r,
(x-h)²+(y-k)²=r²
Therefore, on comparison
center ( 4, -2)
radius r= 4√2
Positive 18, going off the assumption that the tick 2 spaces away from -1 is positive 9.
Step-by-step explanation:

Answer:
k = y/x
Step-by-step explanation:
1/5, 2/10, 3/15 . . . all equal to 1/5 which is what the value of k is; 'k' stands for constant of proportionality