Giải phương trình: \(\left(\sqrt{x-1}+1\right)^3+2\sqrt{x-1}=2-x\)
Đặt \(x-1=a\) (a \(\ge\) 0)
=> pt : \(\left(\sqrt{a}+1\right)^3+2\sqrt{a}=2-\left(a+1\right)\)
\(\Leftrightarrow a\sqrt{a}+3\sqrt{a}+3a+1+2\sqrt{a}=2-a-1\)
\(\Leftrightarrow\left(5+a\right)\sqrt{a}+3a+a+1+1-2=0\)
\(\Leftrightarrow\left(5+a\right)\sqrt{a}+4a=0\)
\(\Leftrightarrow\sqrt{a}\cdot\left[\left(5+a\right)+4\sqrt{a}\right]=0\)
\(\Rightarrow\sqrt{a}=0\) (vì \(\left(5+a\right)+4\sqrt{a}>0\) )
\(\rightarrow\sqrt{x-1}=0\)
\(\rightarrow x=1\)
Vậy pt có nghiệm x = 1
Rút Gọn :
A=\(\dfrac{x-3}{\sqrt{x-1}-\sqrt{2}}\)
Tìm giá trị lớn nhất của hàm số
y=\(\dfrac{x^2+2x+8}{x^2+2x+3}\)
\(\sqrt{3+\sqrt{5+2\sqrt{3}}}.\sqrt{3-\sqrt{5+2\sqrt{3}}}\)
\(\sqrt{\dfrac{3}{4}}\) +\(\sqrt{\dfrac{1}{3}}\) +\(\sqrt{\dfrac{1}{12}}\)
\(\sqrt{7+4\sqrt{3}}.\sqrt{7-4\sqrt{3}}\)
\(\sqrt{2-\sqrt{3}}+\sqrt{2+\sqrt{3}}\)
Rút gọn:
a.\(\sqrt{3a}.\sqrt{27a}-5a\left(a\ge0\right)\)
b.\(\left(2-a\right)^2-\sqrt{0,3}.\sqrt{30a^2}\)
\(\sqrt{2}.\left(\sqrt{5}-\sqrt{3}\right).\sqrt{4}+\sqrt{15}\)
Giải phương trình
\(\left(x^2+x+2\right)^2-\left(x+1\right)^3=x^6+1\)
Thực hiện phép tính:
\(1,\left(\sqrt{12}-2\sqrt{75}\right).\sqrt{3}\)
\(2,\sqrt{3}.\left(\sqrt{12}.\sqrt{27}-\sqrt{3}\right)\)
\(3,\left(7\sqrt{48}+3\sqrt{27}-2\sqrt{12}\right):\sqrt{3}\)
\(4,\left(\sqrt{\dfrac{1}{7}}-\sqrt{\dfrac{16}{7}}+\sqrt{7}\right):\sqrt{7}\)
\(5,\sqrt{\sqrt{5}+2}.\sqrt{\sqrt{5}-2}\)
\(6,\sqrt{9-\sqrt{17}}.\sqrt{9+\sqrt{17}}\)
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