94 - 4d + 6 + 5d = 207. what is the simplified version of the equeation?

X^2 - 4x +(4/2^2) + y^2 + 8y + (8/2^2) = -4 + (4/2^2) + (8/2^2)(x + 2)^2 + (y + 4)^2 = -4 + 4 + 16your center is (-2, -4) and the radius is the sqrt of -4 + 4 + 16 which is 4

20000 as first it increases by 2500 then by 5000 so next it will increase by 10000