Question -
Answer -
The equation of the given circle is x2 + y2 – 8x +10y – 12 = 0.
x2 + y2 – 8x +10y – 12 = 0
⇒ (x2 – 8x) + (y2 + 10y) = 12
⇒ {x2 – 2(x)(4) + 42} + {y2 + 2(y)(5) + 52}– 16 – 25 = 12
⇒ (x – 4)2 + (y +5)2 = 53
, which is of the form (x – h)2 + (y – k)2 = r2, where h =4, k = –5, and 
.
Thus,the centre of the given circle is (4, –5), while its radius is 
.