Imo, it's much easier/faster to estimate, especially since D, E are so far apart from A,B,C:
I knew that √5 ≈ 2.25 so let's call √6 ≈ 2.4 (actual is2.449...)
\(\sqrt{25+10*2.4}+\sqrt{25-10*2.4}\)
\(\sqrt{25+24}+\sqrt{25-24}\)
\(\sqrt{49}+\sqrt{1}\)
\(7 + 1\)
So our answer should be close to 8, D,E are out immediately
C can be rewritten as\(\sqrt{60}\) which is closer than B\(\sqrt{55}\) , so it's C.
...
I knew that √5 ≈ 2.25 so let's call √6 ≈ 2.4 (actual is2.449...)
\(\sqrt{25+10*2.4}+\sqrt{25-10*2.4}\)
\(\sqrt{25+24}+\sqrt{25-24}\)
\(\sqrt{49}+\sqrt{1}\)
\(7 + 1\)
So our answer should be close to 8, D,E are out immediately
C can be rewritten as\(\sqrt{60}\) which is closer than B\(\sqrt{55}\) , so it's C.
...
