\(\sqrt[3]{x^3+9x^2}=x+3\)
\(\Leftrightarrow x^3+9x^2=\left(x+3\right)^3\)
\(\Leftrightarrow x^3+9x^2=x^3+9x^2+27x+27=0\)
\(\Leftrightarrow27x+27=0\)
\(\Leftrightarrow x+1=0\Leftrightarrow x=-1\)
\(\sqrt[3]{x^3+9x^2}=x+3\)
\(\Leftrightarrow x^3+9x^2=\left(x+3\right)^3\)
\(\Leftrightarrow x^3+9x^2=x^3+9x^2+27x+27=0\)
\(\Leftrightarrow27x+27=0\)
\(\Leftrightarrow x+1=0\Leftrightarrow x=-1\)
2. tìm x
a, \(3\sqrt{2x}\) + \(\sqrt{8x}\) - \(\sqrt{18x}\)= 16
b, \(\sqrt{4x+20}\) - \(3\sqrt{x+5}\) + \(\dfrac{4}{3}\) \(\sqrt{9x+45}\) = 6
\(\sqrt[]{x-2}=3\)
\(\sqrt{4x^2}+4x+1=3\)
\(3\sqrt{9x-9}-\sqrt{4x}-4=\sqrt{x-1}+24\)
giúp mk với ạ
tìm x, biết
\(\sqrt{2x+3}=3-\sqrt{5}\)
\(\sqrt{5+\sqrt{7x}}=2+\sqrt{7}\)
\(\left(\sqrt{x}-2\right)\left(5-\sqrt{x}\right)=4-x\)
\(\dfrac{1}{2}\sqrt{x+1}-\dfrac{3}{2}\sqrt{9x-9}+24\sqrt{\dfrac{x-1}{64}}=-17\)
Giải phương trình \(\sqrt{4x^2+5x+1}-2\sqrt{x^2-x+1}=9x-3\)
cho biểu thức p=\(\dfrac{3\left(x+\sqrt{x}-3\right)}{x+\sqrt{x}-2}+\dfrac{\sqrt{x}+3}{\sqrt{x}+2}-\dfrac{\sqrt{x}-2}{\sqrt{x}-1}\)
a rút gọn p
b tìm x để p<15/4
Đề bài: Rút gọn các biểu thức:
1. \(\sqrt{343a}\) + \(\sqrt{63a}\) - \(\sqrt{28a}\) với a lớn bằng 0
2. - \(\sqrt{36b}\) - 1/3\(\sqrt{54b}\) + 1/5\(\sqrt{150b}\) với b lớn bằng 0
3. \(\sqrt{9x+6\sqrt{3x-1}}\) - \(\sqrt{\sqrt{9}}\) - \(\sqrt{\sqrt{9x^2-6x+1}}\) với x > bằng 1/3
4. \(\sqrt{\frac{x^2}{5}}\) + \(\sqrt{\frac{x^2}{20}}\) + \(\sqrt{\frac{49x^2}{20}}\) với x < 0
rút gọn biểu thức
A=\(4\sqrt{\dfrac{25x}{4}}-\dfrac{8}{3}\sqrt{\dfrac{9x}{4}}-\dfrac{4}{3x}\sqrt{\dfrac{9x^3}{64}}\) với \(x>0\)
Tìm x, biết :
a) \(\sqrt{x^2-9}-3\sqrt{x-3}=0\)
b) \(\sqrt{x^2-4}-2\sqrt{x+2}=0\)
\(\sqrt{2x+3}\)\(=\)3-\(\sqrt{5}\)
\(\sqrt{5+\sqrt{7x}}\)\(=\)2+\(\sqrt{7}\)
(\(\sqrt{x}\)-2)(5-\(\sqrt{x}\))\(=\)4-x
\(\dfrac{1}{2}\)\(\sqrt{x-1}\)-\(\dfrac{3}{2}\)\(\sqrt{9x-9}\)+24\(\sqrt{\dfrac{x-1}{64}}\)\(=\)-17