Answer:
[tex] Center = \boxed{1}, \: \boxed{ - 2} \: ; \: Radius = \boxed{3}[/tex]
Step-by-step explanation:
[tex] {x}^{2} + {y}^{2} - 2x + 4y - 4 = 0 \\ \\ ({x}^{2} - 2x + 1 - 1) + ( {y}^{2} + 4y + 4 - 4) - 4 = 0 \\ \\ ( {x}^{2} - 2x + 1) + ( {y}^{2} + 4y + 4) - 9 = 0 \\ \\ {(x - 1)}^{2} + {(y + 2)}^{2} = 9 \\ \\ {(x - 1)}^{2} + {(y + 2)}^{2} = {3}^{2} \\ \\ equating \: it \: with \\ \\ {(x - h)}^{2} + {(y - k)}^{2} = {r}^{2} \\ \\ h = 1 \\ k = - 2 \\ r = 3 \\ \\ center = \boxed{1} \: \boxed{ - 2} \: \: radius = \boxed{3}[/tex]
