Write the standard form equation of the circle described. Give the center and radius.
$x^2+y^2-2x+4y-4=0$

• A. $\(\left\)(x+1\(\right\))^2+\(\left\)(y-2\(\right\))^2=3^2$; Center: $\(\left\)(1,-2\(\right\))$; Radius: $3$
• B. $\(\left\)(x-1\(\right\))^2+\(\left\)(y+2\(\right\))^2=3^2$; Center: $\(\left\)(1,-2\(\right\))$ ; Radius: $3$
• C. $\(\left\)(x+1\(\right\))^2+\(\left\)(y-2\(\right\))^2=3^2$; Center: $\(\left\)(-1,2\(\right\))$; Radius: $9$
• D. $\(\left\)(x-1\(\right\))^2+\(\left\)(y+2\(\right\))^2=3^2$; Center: $\(\left\)(-1,2\(\right\))$; Radius: $3$

Answer: (B)