Question

[Diễm My Võ]

A =\(\sqrt{1}\)+ \(\sqrt{4}+\sqrt{9}+...+\sqrt{81}+\sqrt{100}\)

Answer 1

[Châu Hảo Nhân Tô]

\(\sqrt{1}\)=1

\(\sqrt{4}\)=2

....

\(\sqrt{100}\)=10

=> A= 1+2+...+10=55

Answer 2

[Trần Thủy Tiên]

Ta có: A =\(\sqrt{1}+\sqrt{4}+\sqrt{9}+...+\sqrt{81}+\sqrt{100}\)

             = \(\sqrt{1^2}+\sqrt{2^2}+\sqrt{3^2}+...+\sqrt{9^2}+\sqrt{10^2}\)

             = |1|  + |2| + |3|  + ...+ |9| + |10|

             = 1 + 2 + 3 + 4 +...+ 9 + 10

             = 55