1/ Thu gọn các biểu thức:
A=\(\sqrt{\dfrac{3\sqrt{3}-4}{2\sqrt{3}+1}}-\sqrt{\dfrac{\sqrt{3}+4}{5-2\sqrt{3}}}\)
B=\(\dfrac{x\sqrt{x}-2x+28}{x-3\sqrt{x}-4}-\dfrac{\sqrt{x}-4}{\sqrt{x}+1}+\dfrac{\sqrt{x}+8}{4-\sqrt{x}}\)
Giải pt:
a)\(\sqrt{\left(4-x\right).\left(6+x\right)}=x^2-2x-12\)
b)(x+1).(x+4)=5.\(\sqrt{x^2+5x+28}\)
c)x(x+5)=2.\(\sqrt[3]{x^2+5x-2}-2\)
d)3\(\sqrt{x}+\dfrac{3}{2\sqrt{3}}=2x+\dfrac{1}{2x}-7\)
a) \(\sqrt{x-3}-\sqrt{10-x}\)
b) \(\sqrt{x+4}+\dfrac{2-X}{x^2-16}\)
c) \(\dfrac{\sqrt{2x-3}}{\sqrt{x-4}}\)
d) \(\dfrac{\sqrt{2x-1}}{3x+2}\)
e) \(\dfrac{-2}{\sqrt{x^2+2x+2}}\)
\(\sqrt{28-6\sqrt{3}}\)
\(\sqrt{6-\sqrt{20}}\)
\(\sqrt{2x+3+2\sqrt{\left(x+1\right)\cdot\left(x+2\right)}}\)
\(\sqrt{2x+2-2\sqrt{x^2+2x-3}}\)
\(\sqrt{21+6\sqrt{6}}+\sqrt{21-6\sqrt{6}}\)
A=(\(\dfrac{x\sqrt{x}-1}{x-\sqrt{x}}-\dfrac{x\sqrt{x}+1}{x+\sqrt{x}}\))/(\(1-\dfrac{3-\sqrt{x}}{\sqrt{x}+1}\))
\(A=\sqrt{28}-\sqrt{63}+\dfrac{7+\sqrt{7}}{\sqrt{7}}-\sqrt{\left(\sqrt{7}+1\right)^2}\)
\(B=\left(\dfrac{1}{\sqrt{x}+3}+\dfrac{1}{\sqrt{x}-3}\right)\dfrac{4\sqrt{x}+12}{\sqrt{x}}\) (ĐK x>0; x\(\ne9\))
a)Rút gọn A và B
b) Tìm các giá trị của x để giá trị biểu thức A lớn hơn giá trị biểu thức B
bài 1
a) \(\sqrt{2X+1}\)
b)\(\sqrt{x^2-4}\)
c) \(\dfrac{3}{\sqrt{3X+5}}\)
d) \(\sqrt{X-3}-\sqrt{10-x}\)
e) \(\sqrt{x+4}+\dfrac{2-X}{x^2-16}\)
giải pt
a.\(2\sqrt{x-4}-\dfrac{1}{3}\sqrt{9x-36}=4-\sqrt{x-4}\)
b.\(3\sqrt{x-2}-\sqrt{x^2-4}=0\)
c.\(\sqrt{3x^2-18x+28}+\sqrt{4x^2-24x+45}=-5-x^2+6x\)
Tính DKXD của các căn bậc thức sau:
a)\(\sqrt{2x-4}\)
b)\(\sqrt{\dfrac{3}{-2x+1}}\)
c)\(\sqrt{\dfrac{-3x+5}{-4}}\)
d)\(\sqrt{-5\left(-2x+6\right)}\)
e)\(\sqrt{\left(x^2+2\right)\left(x-3\right)}\)
f)\(\sqrt{\dfrac{x^2+5}{-x+2}}\)
\(\frac{x\sqrt{x}-2x+28}{x-3\sqrt{x}-4}-\frac{\sqrt{x}-4}{\sqrt{x}+1}-\frac{\sqrt{x}+8}{\sqrt{x}-4}\)