\(\frac{3x+9\sqrt{x}}{2}< 1\)
Giải pt: \(\frac{3+x}{3x}=\sqrt{\frac{1}{9}+\frac{1}{x}\sqrt{\frac{4}{9}+\frac{2}{x^2}}}\)
ĐK: x>0
Đặt a=1/x ta được: a>0
\(a+\frac{1}{3}=\sqrt{\frac{1}{9}+a\sqrt{\frac{4}{9}+2a^2}}\)
\(\Leftrightarrow a^2+\frac{1}{9}+\frac{2}{3}a=\frac{1}{9}+a\sqrt{\frac{4}{9}+2a^2}\)
<=>\(a^2+\frac{2}{3}a=a\sqrt{\frac{4}{9}+2a^2}\)
<=>\(a.\left(a+\frac{2}{3}\right)=a\sqrt{\frac{4}{9}+2a^2}\)
<=>\(a+\frac{2}{3}=\sqrt{\frac{4}{9}+2a^2}\)
<=>\(a^2+\frac{4}{9}+\frac{4}{3}a=\frac{4}{9}+2a^2\)
<=>\(a^2-\frac{4}{3}a=0\Leftrightarrow a=0\left(loại\right);a=\frac{4}{3}\)
<=>\(x=\frac{3}{4}\)(loại -3/2)
Vậy x=3/4
Giair phương trình \(\frac{x+3}{3x}=\sqrt{\frac{1}{9}+\frac{1}{x}\sqrt{\frac{4}{9}+\frac{2}{x^2}}}\)
Bài 1. Tìm điều kiện các BPT sau
a, \(\sqrt{20-x}>\sqrt{3x-6}+1\)
b, \(\frac{\sqrt{9-x^2}}{x-1}>\frac{1}{\sqrt{x}}+1\)
c, \(x+\frac{x+1}{\sqrt{x-4}}>2-\frac{2}{x^2-25}\)
d, \(\sqrt{x}>\sqrt{-x}\)
e, \(3x+\frac{4}{\sqrt{x-5}}\le9+\frac{x}{x-6}\)
f, \(\frac{x+2}{10+3x^2}\ge7+\frac{4}{\left(3x+9\right)^2}\)
g, \(\frac{\sqrt{x+2}}{\sqrt{x-2}}+\frac{1}{\left(x-4\right)\left(x+6\right)}\le\frac{3}{\sqrt{8-x}}\)
h, \(\frac{\sqrt{x+6}}{\left|x\right|-\sqrt{x+6}}\ge\sqrt{16-2x}\)
Giải pt: \(\frac{3+x}{3x}=\sqrt{\frac{1}{9}+\frac{1}{x}\sqrt{\frac{4}{9}+\frac{2}{x^2}}}\)
= $\frac{3+x}{3x}=\sqrt{\frac{1}{9}+\frac{1}{x}\sqrt{\frac{4}{9}+\frac{2}{x^2}}}$3+x3x =√19 +1x √49 +2x2
\(P=(\frac{2\sqrt{x}}{\sqrt{x}+3}+\frac{\sqrt{x}}{\sqrt{x}-3}\frac{3x+3}{x-9})\div(\frac{2\sqrt{x}-2}{\sqrt{x}-3}-1)\)
\(\frac{\sqrt{x}}{\sqrt{x}+3}+\frac{2\sqrt{x}}{\sqrt{x}-3}-\frac{3x+9}{x-9}\)
\(\frac{\sqrt{x}}{\sqrt{x}-1}+\frac{1}{\sqrt{x}+2}-\frac{3\sqrt{x}}{x+\sqrt{x}-2}\)
\(\frac{2}{\sqrt{x}-1}+\frac{2}{\sqrt{x}+1}-\frac{5-\sqrt{x}}{x-1}\)
\(\left(\frac{\sqrt{x}+2}{x+2\sqrt{x}+1}-\frac{\sqrt{x}-2}{x-1}\right)\cdot\frac{\sqrt{x}+1}{\sqrt{x}}\)
Rut gon
P=\(\frac{3x+\sqrt{9}-3}{x+\sqrt{x}-2}+\frac{1}{\sqrt{x}-1}+\frac{1}{\sqrt{x}-2}_{ }\)
Giải phương trình sau:
\(\sqrt{\frac{1-2x}{x}}=\frac{3x+x^2}{x^2+1}\)
\(x^2-3x+1=-\frac{\sqrt{3}}{3}\sqrt{x^4+x^2+1}\)
\(x^2-\sqrt{x^3+x}=6x-1\)
\(3\sqrt{x^2-\frac{1}{4}+\sqrt{x^2+x+\frac{1}{4}}}=\frac{1}{2}\left(2x^3+x^2+2x+1\right)\)
\(x^2+\frac{8x^3}{\sqrt{9-x^2}}=9\)
\(A=\left(\frac{3x-3\sqrt{x}-3}{x+\sqrt{x}-2}+\frac{1}{\sqrt{x}-1}-\frac{1}{\sqrt{x}+2}\right):\frac{1}{\sqrt{x}+2}\) với x>=0 x khác
9
\(A=\left(\frac{3x-3\sqrt{x}-3}{x+\sqrt{x}-2}+\frac{1}{\sqrt{x}-1}-\frac{1}{\sqrt{x}+2}\right):\frac{1}{\sqrt{x}+2}\)
\(=\left(\frac{3x-3\sqrt{x}-3}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+2\right)}+\frac{\sqrt{x}+2}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+2\right)}-\frac{\sqrt{x}-1}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+2\right)}\right).\left(\sqrt{x}+2\right)\)
\(=\frac{3x-3\sqrt{x}}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+2\right)}.\left(\sqrt{x}+2\right)\)
\(=\frac{3\sqrt{x}\left(\sqrt{x}-1\right)\left(\sqrt{x}+2\right)}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+2\right)}=3\sqrt{x}\)
tính rồi rút gọn
A=\((\frac{\sqrt{x}}{\sqrt{x}+1}+\frac{1}{\sqrt{x}})\times\frac{x+\sqrt{x}}{\sqrt{x}}\)
B=\(\frac{\sqrt{x}}{\sqrt{x}+3}+\frac{2\sqrt{x}}{\sqrt{x}-3}-\frac{3x+9}{x-9}\)
C=\((\frac{x+\sqrt{x}+10}{x-9}-\frac{1}{\sqrt{x}-3}):\frac{1}{\sqrt{x}-3}\)