Bạn chụp ảnh đăng đề bài lên nhà hoặc bạn viết có kí tự ra ko mk ko biết đề bài chính xác là gì

cvfbhm,

Xin lỗi em ko biết làm , em vẫn chưa lên lớp 9

1)\(\left(\frac{1}{a-\sqrt{a}}+\frac{1}{\sqrt{a}-1}\right):\frac{\sqrt{a}+1}{a-2\sqrt{a}+1}\)

\(=\left(\frac{1}{\sqrt{a}\left(\sqrt{a}-1\right)}+\frac{\sqrt{a}}{\sqrt{a}\left(\sqrt{a}-1\right)}\right)\cdot\frac{\left(\sqrt{a}-1\right)^2}{\sqrt{a}+1}\)

\(=\frac{\sqrt{a}+1}{\sqrt{a}\left(\sqrt{a}-1\right)}\cdot\frac{\left(\sqrt{a}-1\right)^2}{\sqrt{a}+1}\)

\(=\frac{\sqrt{a}-1}{\sqrt{a}}\)

\(\sqrt{12}-2\sqrt{48}+\frac{7}{5}\sqrt{75}\)

=\(2\sqrt{3}-8\sqrt{3}+7\sqrt{3}\)

\(\sqrt{3}\)

\(3\sqrt{2}-4\sqrt{8}+\sqrt{32}-\sqrt{50}\)

= \(3\sqrt{2}-8\sqrt{2}+4\sqrt{2}-5\sqrt{2}\)

= \(-6\sqrt{2}\)

các ý còn lại làm tương tự

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

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

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

\(\sqrt{5}-17\sqrt{3}\)

\(4\sqrt{12}-3\sqrt{45}-5\sqrt{75}+2\sqrt{125}\\ =8\sqrt{3}-9\sqrt{5}-25\sqrt{3}+10\sqrt{5}\\ \sqrt{5}-17\sqrt{3}\)

\(\sqrt{4}+\sqrt{15}-\sqrt{4}-\sqrt{15}-\sqrt{2}-\sqrt{3}\)

\(=-\sqrt{3}-\sqrt{2}\)

\(\sqrt{10}-\sqrt{\dfrac{5}{3}}-\sqrt{18}\)

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

\(=\sqrt{10}-\dfrac{\sqrt{15}}{3}-3\sqrt{2}\)

\(=\dfrac{3\sqrt{10}-\sqrt{15}-9\sqrt{2}}{3}\)