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Đề bài:
So sánh \(\sqrt{17}+\sqrt{26}\)và \(\sqrt{99}\)

Ta có:\(\sqrt{17}+\sqrt{26}>\sqrt{16}+\sqrt{25}=4+5=9\)

Hay \(\sqrt{17}+\sqrt{26}>9\)

= \(\sqrt{17}+\sqrt{26}\)và 9 

\(\sqrt{17}=4,123105626\)

\(\sqrt{26}=5,099019514\)

\(=4,123105626+5,099019514=9,222,25139\)

Vậy \(\sqrt{17}+\sqrt{26}>9\)

Tính kì cục \(\sqrt{16}+\sqrt{25}=4+5=9\)

Thì phải = nhau chứ

cmr là cái j

Lê Thanh Thùy Ngân 

cmr là chứng minh rằng bạn nhé 

ta co: gia tri tuyet doi cua 17+gia tri tuyet doi cua26+1=10,2(da lam tron)

gia tri tuyet doi cua 99=9,9(da lam tron)

ta co:9,9<10,2

Suy ra ..........................................................................................................

                        nguen son dong 

                         mik chả hỉu bạn ghi cái rì . gõ cả dấu bạn nhá

\(\left(\sqrt{26}+3\right)^2=35+6\sqrt{26}\)

\(\left(\sqrt{63}\right)^2=63=35+28\)

mà \(6\sqrt{26}>28\)

nên \(\sqrt{26}+3>\sqrt{63}\)

1) \(3\sqrt{2}-4\sqrt{18}+2\sqrt{32}-\sqrt{50}\)

\(=3\sqrt{2}-12\sqrt{2}+8\sqrt{2}-5\sqrt{2}\)

\(=-6\sqrt{2}\)

2) \(\sqrt{50}-\sqrt{18}+\sqrt{200}-\sqrt{162}\)

\(=5\sqrt{2}-3\sqrt{2}+10\sqrt{2}-9\sqrt{2}\)

\(=3\sqrt{2}\)

3) \(5\sqrt{5}+\sqrt{20}-3\sqrt{45}\)

\(=5\sqrt{5}+2\sqrt{5}-9\sqrt{5}\)

\(=-2\sqrt{5}\)

4) \(5\sqrt{48}-4\sqrt{27}-2\sqrt{75}+\sqrt{108}\)

\(=20\sqrt{3}-12\sqrt{3}-10\sqrt{3}+6\sqrt{3}\)

\(=4\sqrt{3}\)

5) \(\dfrac{1}{2}\sqrt{48}-2\sqrt{75}-\dfrac{\sqrt{33}}{\sqrt{11}}+5\sqrt{1\dfrac{1}{3}}\)

\(=2\sqrt{3}-10\sqrt{3}-\sqrt{3}+\dfrac{10}{3}\sqrt{3}\)

\(=-\dfrac{17}{3}\sqrt{3}\)