Rút gọn các biểu thức sau :
a,\(\dfrac{\sqrt{6}+\sqrt{10}}{\sqrt{21}+\sqrt{35}}\)
b,\(\dfrac{\sqrt{405}+3\sqrt{27}}{3\sqrt{3}+\sqrt{45}}\)
c,\(\dfrac{\sqrt{2}+\sqrt{3}+\sqrt{4}-\sqrt{6}-\sqrt{9}-\sqrt{12}}{\sqrt{2}+\sqrt{3}+\sqrt{4}}\)
d, D=\(\dfrac{2}{x^2-y^2}\cdot\sqrt{\dfrac{9\left(x^2+2xy+y^2\right)}{4}}\) \(\left(vớix\ne y,x\ne-y\right)\)
Giải các pt sau: a)\(\dfrac{9x-7}{\sqrt{7x+5}}=\sqrt{7x+5}\) b)\(\sqrt{4x-20}+3\sqrt{\dfrac{x+5}{9}}-\dfrac{1}{3}\sqrt{9x-45}=4\)
tính
\(a.\sqrt{0,45.0,36}\)
b.\(\dfrac{\sqrt{405}+3\sqrt{27}}{3\sqrt[]{3}+45}\)
c.\(\sqrt{252}-\sqrt{700}+\sqrt{1008}-\sqrt{448}\)
d.\(\left(\sqrt{12}-2\sqrt{75}\right)\sqrt{3}\)
Giải phương trình
\(\sqrt{3x^2-18x+28}+\sqrt{4x^2-24x+45}=-5-x^2+6\)
Áp dụng quy tắc nhân các căn bậc hai, hãy tính :
a) \(\sqrt{10}.\sqrt{40}\)
b) \(\sqrt{5}.\sqrt{45}\)
c) \(\sqrt{52}.\sqrt{13}\)
d) \(\sqrt{2}.\sqrt{162}\)
Rút gọn:
a)\(\dfrac{\sqrt{6}+\sqrt{10}}{\sqrt{21}+\sqrt{35}}\)
b)\(\dfrac{\sqrt{405}+3\sqrt{27}}{3\sqrt{3}+\sqrt{45}}\)
c)\(\dfrac{\sqrt{2}+\sqrt{3}+\sqrt{4}-\sqrt{6}-\sqrt{9}-\sqrt{12}}{\sqrt{2}+\sqrt{3}+\sqrt{4}}\)
d)\(\dfrac{\sqrt{6-2\sqrt{5}}}{\sqrt{5}-1}\)
I.
1, \(\sqrt{8}-3\sqrt{32}+\sqrt{72}\)
2, \(6\sqrt{12}-2\sqrt{48}+5\sqrt{75}-7\sqrt{108}\)
3, \(\sqrt{20}+3\sqrt{45}-6\sqrt{80}-\dfrac{1}{3}\sqrt{125}\)
4, \(2\sqrt{5}-\sqrt{125}-\sqrt{80}\)
5, \(3\sqrt{2}-\sqrt{8}+\sqrt{50}-4\sqrt{32}\)
a) \(\sqrt{\frac{125}{3^5.4^3}}\)
b) \((\sqrt{45}-\sqrt{20}+\sqrt{5}):\sqrt{6}\)
c) \((\frac{\sqrt{1}}{7}-\frac{\sqrt{16}}{7}+\sqrt{7}):\sqrt{7}\)
d) \(\sqrt{32.200}\)
e)\(\sqrt{\frac{9}{16}:\frac{25}{36}}\)
Mn giúp mình với ạ!
giải pt
a)\(\sqrt{\dfrac{2x-3}{x-1}}=2\)
b)\(\dfrac{\sqrt{2x-3}}{\sqrt{x-1}}=2\)
c)\(\sqrt{4x^2-9}=2\sqrt{2x+3}\)
d)\(\dfrac{9x-7}{\sqrt{7x+5}}=\sqrt{7x+5}\)
e)\(\sqrt{4x-20}+3\sqrt{\dfrac{x-5}{9}}-\dfrac{1}{3}\sqrt{9x-45}=4\)