1. The problem asks to write the standard form equation of each circle given its center and radius. 2. The standard form equation of a circle with center $(h, k)$ and radius $r$ is: $$ (x - h)^2 + (y - k)^2 = r^2 $$ 3. For Graph 1: Center is $(0,0)$ and radius is $3$. $$ (x - 0)^2 + (y - 0)^2 = 3^2 $$ $$ x^2 + y^2 = 9 $$ 4. For Graph 2: Center is $(0,0)$ and radius is $4$. $$ (x - 0)^2 + (y - 0)^2 = 4^2 $$ $$ x^2 + y^2 = 16 $$ 5. For Graph 3: Center is approximately $(2,-1)$ and radius is $3$. $$ (x - 2)^2 + (y - (-1))^2 = 3^2 $$ $$ (x - 2)^2 + (y + 1)^2 = 9 $$ 6. For Graph 4: Center is approximately $(-2,0)$ and radius is $3$. $$ (x - (-2))^2 + (y - 0)^2 = 3^2 $$ $$ (x + 2)^2 + y^2 = 9 $$ Final answers: Graph 1: $$ x^2 + y^2 = 9 $$ Graph 2: $$ x^2 + y^2 = 16 $$ Graph 3: $$ (x - 2)^2 + (y + 1)^2 = 9 $$ Graph 4: $$ (x + 2)^2 + y^2 = 9 $$