If `(-3,2)` lie on the circle `x^2+y^2+2gx+2fy+c=0` which is concentric with the circle `x^2+y^2+6x+8fy-5=0t h e n=`
`(a)11` `(b) -11 ` `(c) 24 ` (d) none of these

Explanation

Let us assume the concentric circle be `x^2 + y^2 + 6x + 8y + d = 0. ..... (i)`

Substituting (- 3,2) in (i)

`⇒(- 3)^2 + 2^2 + 6(- 3) + 8(2) + d = 0 `

`⇒ 9 + 4 - 18 + 16 + d = 0 `

`⇒ d = - 11`

Substituting value of d in (ii) we get

` ⇒ x^2 + y^2 + 6x + 8y - 11 = 0`

Comparing with `x^2 + y^2 + 2gx + 2fy + c = 0 `

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