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> $x^2+y^2=4x+8y+5$ intersects $3x-4y=m$ at two distinct points. What are $m$'s possible values?
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I got that the centre of the circle is $C=(2,4)$ and its radius is $r=5$. If the line $l$ intersects the circle at two points, the distance between the line and $C$ is less than $r$:
$$\frac{|6-16-m|}5<5\implies-35<m<15$$
Is this correct?