Tìm GTNN:
P=\(\frac{81x^2+18225x+1}{9x}-\frac{6\sqrt{x}+8}{x+1}\) với x>0.
tìm GTNN của \(P=\frac{81x^2+18225x+1}{9x}-\frac{6\sqrt{x}+8}{x+1}\) với x>0
\(tìmMinP=\frac{81x^2+18225x+1}{9x}-\frac{6\sqrt{x}+8}{x+1}vớix>0\)
Tìm MIN của \(P=\frac{81x^2+18225x+1}{9x}-\frac{6\sqrt{x}+8}{x+1},x>0\)
Min P = (81x^2 + 18225x +1 ) :9x - (6√x +8):(x+1)
\(A=\left(\frac{\sqrt{x}-1}{3\sqrt{x}-1}-\frac{1}{3\sqrt{x}+1}+\frac{8\sqrt{x}}{9x-1}\right):\left(1+\frac{3\sqrt{x}-1}{3\sqrt{x}+1}\right),\left(x>0,x\ne\frac{1}{9}\right)\)
1. Rút gọn A
2. Tìm x để \(P=\frac{5}{6}\)
\(A=\left[\frac{\left(\sqrt{x}-1\right)\left(3\sqrt{x}+1\right)-\left(3\sqrt{x}-1\right)+8\sqrt{x}}{\left(3\sqrt{x}-1\right)\left(3\sqrt{x}+1\right)}\right]:\frac{6\sqrt{x}}{3\sqrt{x}+1}\)
\(A=\left[\frac{3x-2\sqrt{x}-1-3\sqrt{x}+1+8\sqrt{x}}{\left(3\sqrt{x}-1\right)\left(3\sqrt{x}+1\right)}\right].\frac{3\sqrt{x}+1}{6\sqrt{x}}\)
\(A=\frac{3x+3\sqrt{x}}{3\sqrt{x}-1}.\frac{1}{6\sqrt{x}}\)
\(A=\frac{3\sqrt{x}\left(\sqrt{x}+1\right)}{3\sqrt{x}-1}.\frac{1}{6\sqrt{x}}\)
\(A=\frac{\sqrt{x}+1}{6\sqrt{x}-2}\)
\(A=\frac{5}{6}\Leftrightarrow\frac{\sqrt{x}+1}{6\sqrt{x}-2}=\frac{5}{6}\)
\(\Leftrightarrow6\sqrt{x}+6=30\sqrt{x}-10\)
\(\Leftrightarrow24\sqrt{x}=16\)
\(\Leftrightarrow\sqrt{x}=\frac{2}{3}\Leftrightarrow x=\frac{4}{9}\)
\(A=\left[\frac{\left(\sqrt{x}-1\right)\left(3\sqrt{x}+1\right)-\left(3\sqrt{x}-1\right)+8\sqrt{x}}{\left(3\sqrt{x}-1\right)\left(3\sqrt{x}+1\right)}\right]\div\frac{6\sqrt{x}}{3\sqrt{x}+1}\)
\(A=\left[\frac{3x-2\sqrt{x}-1-3\sqrt{x}+1+8\sqrt{x}}{\left(3\sqrt{x}-1\right)\left(3\sqrt{x}+1\right)}\right]\times\frac{3\sqrt{x}+1}{6\sqrt{x}}\)
\(A=\frac{3x+3\sqrt{x}}{3\sqrt{x}-1}\times\frac{1}{6\sqrt{x}}\)
\(A=\frac{3\sqrt{x}\left(\sqrt{x}+1\right)}{3\sqrt{x}-1}\times\frac{1}{6\sqrt{x}}\)
\(A=\frac{\sqrt{x}+1}{6\sqrt{x}-2}\)
\(A=\frac{5}{6}\)
\(\Leftrightarrow\frac{\sqrt{x}+1}{6\sqrt{x}-2}=\frac{5}{6}\)
\(\Leftrightarrow6\sqrt{x}+6=30\sqrt{x}-10\)
\(\Leftrightarrow24\sqrt{x}=16\)
\(\Leftrightarrow\sqrt{x}=\frac{2}{3}\)
\(\Leftrightarrow x=\frac{4}{9}\)
Lâu lắm ko inbox nên hôm nay quá nhiều bài cho anh em
1. \(2x^2-11x+21-3\sqrt[3]{4x-4}=0\)
2.\(\sqrt{\frac{x^3+1}{x^2+1}}=\frac{2}{5}\)
3.\(\left(2x+7\right)\sqrt{2x+7}=x^2+9x+7\)
4.\(\sqrt[3]{81x-8}=x^3-2x^2+\frac{4}{3}x-2\)
5.\(32x^4-80x^3+50x^2+4x-3-4\sqrt{x-1}=0\)
6.\(\sqrt{5x^3+2x^2+12x-7}=\frac{x^2}{2}+2x-3\)
\Nếu dùng liên hợp phải chứng minh vế lủng củng vô nghiệm
con 6 tách trong căn thành nhân tử nhân 2 vế cho 2 rồi tách thành hđt
Tìm GTNN của E = \(9x+\frac{1}{9x}-\frac{6\sqrt{x}+8}{x+1}+2020\)
Cho biểu thức : \(C=\left(\frac{\sqrt{x}-1}{3\sqrt{x}-1}-\frac{1}{3\sqrt{x}-1}+\frac{8\sqrt{x}}{9x-1}\right):\left(1+\frac{3\sqrt{x}-1}{3\sqrt{x}+1}\right),x>0,x\ne\frac{1}{9}\)
Rút gọn CTìm \(x\) để \(P=\frac{5}{6}\)\(\left(\frac{\sqrt{x}-1}{3\sqrt{x}-1}-\frac{1}{3\sqrt{x}+1}+\frac{8\sqrt{x}}{9x-1}\right):\left(1-\frac{3\sqrt{x}-2}{3\sqrt{x}+1}\right)\)\
Tìm ĐKXĐ và rút gọn
mọi người cố gắng giúp em với nhé
\(ĐKXĐ:x\ge0;x\ne\frac{1}{9}\)
\(\left(\frac{\sqrt{x}-1}{3\sqrt{x}-1}-\frac{1}{3\sqrt{x}+1}+\frac{8\sqrt{x}}{9x-1}\right):\left(1-\frac{3\sqrt{x}-2}{3\sqrt{x}+1}\right)\)
\(\left(\frac{\left(\sqrt{x}-1\right)\left(3\sqrt{x}+1\right)-3\sqrt{x}+1+8\sqrt{x}}{9x-1}\right):\left(\frac{3\sqrt{x}+1-3\sqrt{x}+2}{3\sqrt{x}+1}\right)\)
\(\frac{3x-3\sqrt{x}+\sqrt{x}-1+5\sqrt{x}+1}{9x-1}.\frac{3\sqrt{x}+1}{3}\)
\(\frac{3x+3\sqrt{x}}{9x-1}.\frac{3\sqrt{x}+1}{3}\)
\(\frac{x+\sqrt{x}}{3\sqrt{x}-1}\)