Với `x >= 0,x \ne 25` có:
`3/[\sqrt{x}+5]+[20-2\sqrt{x}]/[x-25]`
`=[3(\sqrt{x}-5)+20-2\sqrt{x}]/[(\sqrt{x}-5)(\sqrt{x}+5)]`
`=[3\sqrt{x}-15+20-2\sqrt{x}]/[(\sqrt{x}-5)(\sqrt{x}+5)]`
`=[\sqrt{x}+5]/[(\sqrt{x}-5)(\sqrt{x}+5)]=1/[\sqrt{x}-5]`
\(B=(\dfrac{\sqrt{x}}{\sqrt{x}-2}-\dfrac{2}{\sqrt{x}+2}):\dfrac{x+4}{\sqrt{x}+2}\)
Rut gon
rut gon pt
\(\dfrac{x+\sqrt{x}}{\sqrt{x}+1}+\dfrac{x-\sqrt{x}}{\sqrt{x}-1}\)
1,Rut gon \(\left(\dfrac{\sqrt{x}}{\sqrt{x}+3}+\dfrac{3}{\sqrt{x}-3}\right):\dfrac{\sqrt{x}-3}{x-9}\) voi x>0,x khac 9
2.Cho 2 đt có ptr (d) y=(m2-3)x+4 và (d') y=2mx+1 Tìm m để 2 đt (d) và (d')song song vs nhau
\(\dfrac{2\sqrt{x}}{x-5\sqrt{x}+6}+\dfrac{2\sqrt{x}+1}{\sqrt{x}-3}+\dfrac{\sqrt{x}+3}{2-\sqrt{x}}\) RÚT GON
\(\dfrac{2\sqrt{x}-9}{x-5\sqrt{x}+6}+\dfrac{2\sqrt{x}+1}{\sqrt{x}-3}+\dfrac{\sqrt{x}+3}{2-\sqrt{x}}\) RÚT GON
a : \(\dfrac{3}{\sqrt{x}-5}+\dfrac{20-2\sqrt{x}}{x-25}\)với x ≥ 0 x ≠ 25
b : \(\dfrac{\sqrt{x}}{\sqrt{x}-3}+\dfrac{2\sqrt{x}-2}{x-9}\)với x ≥ 0 x ≠ 9
c : \(\dfrac{\sqrt{x}-1}{\sqrt{x}+2}+\dfrac{5\sqrt{x}-2}{x-4}\)với x ≥ 0 x ≠ 4
d : \(\left(\dfrac{x-2}{x+2\sqrt{x}}+\dfrac{1}{\sqrt{x}+2}\right).\dfrac{\sqrt{x}+1}{\sqrt{x}-1}\)với ≥ 0 x ≠ 1
d) \(x-5\sqrt{x}+6=0\)
e) \(\sqrt{x-1}+\dfrac{3}{2}\sqrt{4x-4}-\dfrac{2}{5}\sqrt{25x-25}=4\)
f) \(\sqrt{x-5}+\sqrt{4x-20}-\dfrac{1}{3}\sqrt{9x-45}=6\)
\(B=\dfrac{3}{\sqrt{x+5}}+\dfrac{20-2\sqrt{x}}{x-25}\)
a) \(\sqrt{4x^2-9}=2\sqrt{x+3}\)
b) \(\sqrt{4x+20}+3\sqrt{\dfrac{x-5}{9}}-\dfrac{1}{3}\sqrt{9x-45}=4\)
c) \(\dfrac{2}{3}\sqrt{9x-9}-\dfrac{1}{4}\sqrt{16x-16}+27\sqrt{\dfrac{x-1}{81}}=4\)
d)\(5\sqrt{\dfrac{9x-27}{25}}-7\sqrt{\dfrac{4x-12}{9}}-7\sqrt{x^2-9}+18\sqrt{\dfrac{9x^2-81}{81}}=0\)
Tính GTLN của biểu thức A.
\(A=\dfrac{1-\sqrt{x}}{\sqrt{x}+2}\)(đk: \(x\ge0,x\ne1,x\ne4\))
B2. Giải pt
\(\sqrt{x-3}+\sqrt{y-5}+\sqrt{z-4}=20-\dfrac{4}{\sqrt{x-3}}-\dfrac{9}{\sqrt{y-5}}-\dfrac{25}{\sqrt{z-4}}\)
