Giai pt: \(x+4\sqrt{x+3}+2\sqrt{3-2x}=11\)
Giai pt ;\(\sqrt{2x^2-9x+4}+3\sqrt{2x-1}=\sqrt{2x^2+21x-11}\)
bài này đâu phải của lớp 1 đâu?!!
HAPPY NEW YEAR ^-^
Giai pt
\(\sqrt{2x+1}-2\sqrt{2-x}=3\sqrt[4]{\left(1-2x\right)\left(x-2\right)}\)
giai pt
\(\sqrt{x+3}-\sqrt{x-1}=\sqrt{2x+2}\)
\(\sqrt{x^2-x+4}-x^2+x+2=0\)
\(\sqrt[3]{x+7}+\sqrt[3]{1-x}=2\)
a) \(\sqrt{x+3}-\sqrt{x-1}=\sqrt{2x+2}\)
Điều kiện: \(\hept{\begin{cases}x+3\ge0\\x-1\ge0\\2x+2\ge0\end{cases}}\Leftrightarrow\hept{\begin{cases}x\ge-3\\x\ge1\\x\ge-1\end{cases}\Leftrightarrow x\ge1}\)
\(\Leftrightarrow\left(\sqrt{x+3}-\sqrt{x-1}\right)^2=\left(\sqrt{2x+2}\right)^2\)
\(\Leftrightarrow x+3-2\sqrt{\left(x+3\right)\left(x-1\right)}+x-1=2x+2\)
\(\Leftrightarrow2x+2-2\sqrt{\left(x+3\right)\left(x-1\right)}=2x+2\)
\(\Leftrightarrow-2\sqrt{\left(x+3\right)\left(x-1\right)}=0\)
\(\Leftrightarrow\left(x+3\right)\left(x-1\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x+3=0\\x-1=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=-3\left(l\right)\\x=1\left(n\right)\end{cases}}\)
Vậy \(S=\left\{1\right\}\)
Giai cac pt:
a, \(2x^2-8x+\sqrt{x^2-4x-5}=13\)
b, \(\sqrt{1-x}+\sqrt{4+x}=3\)
c, \(x^3+4x+5=2\sqrt{2x+3}\)
d, \(2\sqrt{2x+4}+4\sqrt{2-x}=\sqrt{9x^2-16}\)
e, \(\sqrt[3]{x-2}+\sqrt{x+1}=3\)
Giải pt \(x+4\sqrt{x+3}+2\sqrt{3-2x}=11\)
\(\left(x-1\right)+4.\left(\sqrt{x+3}-2\right)+2.\left(\sqrt{3-2x}-1\right)=0\)
\(x-1+\dfrac{4.\left(x+3-4\right)}{\sqrt{x+3}+2}+\dfrac{2.\left(3-2x-1\right)}{\sqrt{3-2x}+1}=0\)
=> x-1+\(\dfrac{4.\left(x-1\right)}{\sqrt{x+3}+2}+\dfrac{4.\left(1-x\right)}{\sqrt{3-2x}+1}=0\)
=> (x-1).\(\left(\dfrac{4}{\sqrt{x+3}+2}+\dfrac{4}{\sqrt{3-2x}+1}\right)=0\)
=> x=1 (do \(\dfrac{4}{\sqrt{x+3}+2}+\dfrac{4}{\sqrt{3-2x}+1}>0\)
giai pt sau
\(\sqrt{3x-1}-\sqrt{x+2}.\sqrt{3x^2+7x+2}+4=4x-2\)
\(x^2-5x+3.\sqrt{2x-1}=2.\sqrt{14-2x}+5\)
\(\left(x+1\right)\left(x+4\right)-3\sqrt{x^2+5x+2}=6\)
nhiều thế giải ko đổi đâu bạn
đkxđ : \(\frac{1}{2}\le x\le7\)
\(x^2-5x+3\sqrt{2x-1}=2\sqrt{14-2x}+5\)
\(\Leftrightarrow\left(x^2-5x\right)+3\left(\sqrt{2x-1}-3\right)=2\left(\sqrt{14-2x}-2\right)\)
\(\Leftrightarrow x\left(x-5\right)+\frac{3.\left(2x-10\right)}{\sqrt{2x-1}+3}+\frac{2.\left(2x-10\right)}{\sqrt{14-2x}+2}=0\)
\(\Leftrightarrow\left(x-5\right)\left(x+\frac{6}{\sqrt{2x-1}+3}+\frac{4}{\sqrt{14-2x}+2}\right)=0\)
\(\Leftrightarrow x=5\)
còn bài a,c lười đánh lắm
giai he pt pt(1): x2(y+3)(x+2)-\(\sqrt{2x+3}\)=0 ;pt(2): 4x -4\(\sqrt{2x+3}\) +x3\(\sqrt{\left(y+3\right)^3}\) +9=0
GIAI PT
\(\sqrt{-x^2+4x+12}-\sqrt{-x^2+2x+3}=\sqrt{3}-x^2\)
Xét VT
ĐKXĐ \(-1\le x\le3\)
\(XH:\left(-x^2+4x+12\right)-\left(-x^2+2x+3\right)=2x+9\ge0\)
VT^2 = \(-x^2+4x+12-x^2+2x+3+2\sqrt{\left(-x^2+4x+12\right)\left(-x^2+2x+3\right)}\)
<=> \(VT^2=-2x^2+6x+15+2\sqrt{\left(x+2\right)\left(6-x\right)\left(x+1\right)\left(3-x\right)}\)
= \(\left(x+2\right)\left(3-x\right)+\left(6-x\right)\left(x+1\right)+2\sqrt{\left(x+2\right)\left(3-x\right)\left(6-x\right)\left(x+1\right)}+3\)
= \(\left(\sqrt{\left(x+2\right)\left(3-x\right)}+\sqrt{\left(6-x\right)\left(x+1\right)}\right)^2+3\ge3\)
=> VT \(\ge\sqrt{3}\) dấu '=' xảy khi \(\sqrt{\left(x+2\right)\left(3-x\right)}=\sqrt{\left(6-x\right)\left(x+1\right)}\)
<=> \(-x^2+x+6=-x^2+5x+6\Rightarrow x=0\)
VP = \(\sqrt{3}-x^2\le\sqrt{3}\)
dấu '=' xảy ra khi tai x = 0
Vậy VP = VT = căn 3 tại x = 0
Giai pt:
a, \(x^2+\sqrt[3]{x^4-x^2}=2x+1\)
b, \(x+1+\sqrt{x^2-4x+1}=3\sqrt{x}\)
c, \(\sqrt{2x^2+7x+10}+\sqrt{2x^2+x+4}=3\left(x+1\right)\)
d, \(2\left(x^2-3x+2\right)=3\sqrt{x^3+8}\)
Mong moi nguoi giup do, em can gap !!!