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What is the value of positive square root of $$69+28\sqrt{5}$$ ?
Let $$x=69+28\sqrt5$$
=> $$x=69+2(2)(7)(\sqrt{5})$$
=> $$x=(49)+(20)+2(7)(2\sqrt5)$$
=> $$x=(7)^2+(2\sqrt5)^2+2(7)(2\sqrt5)$$
=> $$x=(7+2\sqrt5)^2$$
=> Positive square root of $$x=7+2\sqrt5$$
=> Ans - (A)
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