For an algebraic solution to the first problem, please see the attached document.
An easier approach would be to ballpark:
[Sqrt(9 + Root80) + Sqrt(9 - Root80)]^2
=[Sqrt(9 + almost 9) + Sqrt(9 - almost 9)]^2
= [Sqrt(18) + Sqrt(fraction)]^2 approximately
=[Sqrt(18) + Sqrt(fraction)]*[Sqrt(18) + Sqrt(fraction)]
= 18 + more
The only answer choice larger than 18 is E.
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