Question 1116390
Radii, r and r+4


{{{pi*r^2+pi*(r+4)^2=106pi}}}

{{{r^2+(r+4)^2=106}}}

{{{r^2+r^2+8r+16-106=0}}}

{{{2r^2+8r-90=0}}}

{{{r^2+4r-45=0}}}

{{{(r-5)(r+9)=0}}}

{{{highlight(r=5)}}}--------radius of the small circle
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{{{highlight(9)}}}----------radius of the big circle