bình phương 2 vế được :
x + 4\(\sqrt{x-4}\) =4
<=> (x-4) + 4\(\sqrt{x-4}\) +4 =4
<=> ( \(\sqrt{x-4}\)+ 2)2=4
vì\(\sqrt{x-4}\) ≥0 nên VT ≥4
dấu bằng xảy ra khi \(\sqrt{x-4}\)=0 <=> x=4
1, \(\sqrt{x-1}+\sqrt{x-4}=5\)
2, \(2x-7\sqrt{x}+5=0\)
3, \(\sqrt{2x+1}+\sqrt{x-3}=2\sqrt{x}\)
4, \(x-4\sqrt{x}+2021\sqrt{x-4}+4=0\)
5, \(\sqrt{2x-3}-\sqrt{x+1}=7\left(4-x\right)\)
1) x-\(7\sqrt{x-3}\) -9=0 2) \(\sqrt{x+3}\) =5-\(\sqrt{x-2}\) 3) \(\sqrt{x-4\sqrt{x+4}}\) =3 4) \(\sqrt{8-\dfrac{2}{3}x}-5\sqrt{2}\) =0 5) \(\sqrt{x^2-4x+4}\) =2-x
Giải các phương trình sau :
1/\(\sqrt{x+2+4\sqrt{x-2}}=5\)
2/\(\sqrt{x+3+4\sqrt{x-1}}=2\)
3/\(\sqrt{x+\sqrt{2x-1}}=\sqrt{2}\)
4/\(\sqrt{x-2+\sqrt{2x-5}}=3\sqrt{2}\)
i) \(2\sqrt{x+2+2\sqrt{x+1}}-\sqrt{x+1}=4\)
ii)\(\sqrt{x+4}+\sqrt{x-4}=2x-12+2\sqrt{x^2-16}\)
chứng minh p=\(\left(\dfrac{\sqrt[4]{x^2}-\sqrt[4]{x}}{1-\sqrt[4]{x}}+\dfrac{1+\sqrt{x}}{\sqrt[4]{x}}\right)^2-\dfrac{\sqrt{1+\dfrac{2}{\sqrt{x}}+\dfrac{1}{x}}}{1+\sqrt{x}}\)(x>0)không phụ thuộc vào x
Rút gọn:
\(A=\sqrt{x+\sqrt{x^2-4}}+\sqrt{x-\sqrt{x^2-4}}\)
\(B=\sqrt{10x-6\sqrt{x^2-2x}-2}+\sqrt{5x+4\sqrt{x^2-2x}-2}\)
\(C=\frac{\sqrt{2+\sqrt{-x^2+6x-8}}}{x-3}\)
\(D=\sqrt{\frac{17}{4}+2\sqrt{4-x^2}+\sqrt{4+2\sqrt{4-x^2}}}\)
Giúp mình với các bạn
\(2x^4+8x=4\sqrt{4+x^4}+4\sqrt{x^4-4}\)
\(^{x^3-3x^2-8x+40-8\sqrt[4]{4x+4}=0}\)
\(\sqrt[4]{x}+\sqrt[4]{1-x}+\sqrt{x}-\sqrt{1-x}=\sqrt{2}+\sqrt[4]{8}\)
11. P=\(\left(\dfrac{\sqrt{x}+2}{\sqrt{x}-2}-\dfrac{\sqrt{x}-2}{\sqrt{x}+2}-\dfrac{4x}{4-x}\right);\dfrac{x+5\sqrt{x}+6}{x-4}\)
a.rút gọn
b. tính giá trị P khi x=\(\sqrt{9+4\sqrt{5}}-\sqrt{9-4\sqrt{5}}\)
c. tìm x để P=2
( \(\dfrac{\sqrt{x}}{\sqrt{x}-2}\) + \(\dfrac{\sqrt{x}-1}{\sqrt{x}+2}\) - \(\dfrac{3\sqrt{x}+2}{x-4}\) ) : \(\dfrac{\sqrt{x}-2}{x-4}\) ( với x ≥ 0; x ≠ 4)
RÚT GỌN Ạ
Cho 0<x<2. Chứng minh rằng:
\(\dfrac{4-\sqrt{4-x^2}}{\sqrt{\left(2+x\right)^3}+\sqrt{\left(2-x\right)^3}}\) + \(\dfrac{4+\sqrt{4-x^2}}{\sqrt{\left(2+x\right)^3}-\sqrt{\left(2-x\right)^3}}\) = \(\dfrac{\sqrt{2+x}}{x}\)
