By doing a two step equation
9(2k+3)+2=11 (k-y)
k=-11/7 y+ -29/7
1-(-4)^2
1-(-4 times -4)
1-(16)
1-16
-15
Area shaded = Area big circle- Area of small circle;
200 pi= pi•(2x)^2 -pi•6^2;
200pi= pi•4x^2 -pi•36;
200pi=pi•4(x^2 -9) divide both sides by 4pi;
50=x^2 -9; So x=sqrt(59)~7.68cm