The correct option is A 7 cmand 3 cm
Let r be the radius of one circle and,
10−r be the radius of other circle.
The area of the first circle is πr2
The area of the first circle is π(10−r2)
Given,
The sum of these areas is 58πcm2
Therefore,
πr2+π(10−r)2=58π
=>r2+(10−r)2=58 [dividing both sides by π]
=>r2+(10)2+(r)2−2(10)(r)=58
=>r2+100+r2−20r=58
=>2r2−20r+42=0
=>r2−10r+21=0 [dividing both sides by 2]
=>r2−7r−3r+21=0
=>r(r−7)−3(r−7)=0
=>(r−7)(r−3)=0
r=3cm and r=7cm