Step 1
Given;
Step 2
A)
[tex]\begin{gathered} Equation\text{ of a circle is;} \\ (x-h)^2+(y-k)=r^2 \\ (x-0)^2+(y-0)^2=(\frac{100}{2})^2 \\ x^2+y^2=50^2 \end{gathered}[/tex]
B)
[tex]\begin{gathered} x=h-p \\ x=0-70 \\ x=-70 \\ x=\frac{1}{4(-70)}(y-0)^2+60 \end{gathered}[/tex][tex]x=\frac{1}{-280}(y)^2+60[/tex]
C)
[tex][/tex]
