Với giá trị nào của x thì mỗi căn thức sau có nghĩa:
1 \(\sqrt{9x^2-6x+1}\) 6 \(\sqrt{x^2-16}\) 11 \(\frac{1}{\sqrt{9-12x+4x^2}}\)
2 \(\sqrt{-x^2+2x-1}\) 7 \(\sqrt{x\left(x+2\right)}\) 12 \(\sqrt{x^2-2x-3}\) \(\sqrt{4x^2+3}\)
3\(\frac{1}{\sqrt{x+2\sqrt{x-1}}}\) 8 \(\sqrt{|x-1|-3}\) 13 \(\sqrt{x^2-3}\)
4 \(\sqrt{-|x+5|}\) 9 \(\sqrt{|x|-1}\) \(\sqrt{x^2+1}\)
5 \(\sqrt{x^2-3}\) 10\(\sqrt{x-2\sqrt{x-1}}\)
Bài 2
a) A= \(\sqrt{\left(1-\sqrt{2}\right)^2}+\sqrt{\left(-2\right)^6}-\sqrt{\left(1+\sqrt{2}\right)^2}\)
b) B= \(\sqrt{7+2\sqrt{6}}+\sqrt{7-2\sqrt{6}}\)
c) C= \(\sqrt{7-4\sqrt{3}}\)
d) D= \(2\sqrt{7+4\sqrt{3}}-\sqrt{13-4\sqrt{3}}\)
e) E= \(\frac{1}{1+\sqrt{3}}+\frac{1}{\sqrt{3}+\sqrt{5}}+...+\frac{1}{\sqrt{79}+\sqrt{81}}\)
Bài 4:
a) \(\sqrt{x-1}=2\)
b) \(\sqrt{x^2-3x+2}=\sqrt{2}\)
c) \(\sqrt{4x+1}=x+1\)
d) \(\sqrt{x+2\sqrt{x-1}}-\sqrt{x-2\sqrt{x-1}}=2\)
e) \(\sqrt{x^2-4x+5}+\sqrt{x^2-4x+8}+\sqrt{x^2-4x+9}=3+\sqrt{5}\)
f)
giải các pt
1, \(\sqrt{2x^2+8x+6}+\sqrt{x^2-1}=2x+2\)
2, \(\sqrt{x+2\sqrt{x-1}}-\sqrt{x-2\sqrt{x-1}}=2\)
3, \(\sqrt{x^2+x+4}+\sqrt{x^2+x+1}=\sqrt{2x^2+2x+9}\)
4, \(2x^2+\sqrt{x^2-4x+12}=4x+8\)
5, \(\sqrt{x+3-4\sqrt{x-1}}+\sqrt{x+8-6\sqrt{x-1}}=1\)
Câu 1: Giải phương trình:
a) \(\sqrt{x}+\sqrt{2-x}=2\)
b) \(\sqrt{4x-12}+\frac{1}{3}\sqrt{9x-27}=4+\sqrt{x-3}\)
c) \(6\sqrt{4x+8}-\sqrt{9x+18}-2\sqrt{x+2}=21\)
d) \(\left(3-2\sqrt{x}\right)\left(2+3\sqrt{x}\right)=16-6x\)
Câu 2: Cho \(\sqrt{3-x}+\sqrt{5-x}=2\)
Hãy tính: \(A=\sqrt{3-x}-\sqrt{5-x}\)
Giải PT:
a) \(\dfrac{9x-7}{\sqrt{7x+5}}=\sqrt{7x+5}.\)
b) \(\sqrt{4x-20}+3\sqrt{\dfrac{x-5}{9}}-\dfrac{1}{3}\sqrt{9x-45}=4.\)
c) \(2x-x^2+\sqrt{6x^2-12x+7}=0.\)
d) \(\left(x+1\right)\left(x+4\right)-3\sqrt{x^2+5x+2}=6.\)
Tìm x:
a) \(\left(5x-6\right)^2-\frac{1}{\sqrt{5x-7}}=x^2-\frac{1}{\sqrt{x-1}}\)
b) \(4x^3+x-\left(x+1\right)\sqrt{2x+1}=0\)
c) \(\frac{\sqrt{x+1}-2}{\sqrt[3]{2x+1}-3}=\frac{1}{x+2}\)
d) \(-2x^3+10x^2-17x+8=2x^2\sqrt[3]{5x-x^2}\)
e) \(9x^2-28x+21=\sqrt{x-1}\)
f) \(3x\left(2+\sqrt{9x^2+3}\right)+\left(4x+2\right)\sqrt{1+x+x^2}+1=0\)
Mng giúp em với ạ, em cảm ơn
Giải phương trình
1) \(3x^2+6x-\frac{4}{3}=\sqrt{\frac{x+7}{3}}\)
2) \(9x^2-x-4=2\sqrt{x+3}\)
3) \(x^2+\sqrt{x+5}=5\)
4) \(2x^2+2x+1=\left(4x-1\right).\sqrt{x^2+1}\)
5) \(x\sqrt{x^2-x+1}+2\sqrt{3x+1}=x^2+x+3\)
Rút gọn
\(A=\left(\frac{\sqrt{x}-1}{3\sqrt{x}-1}-\frac{1}{3\sqrt{x}+1}+\frac{8\sqrt{x}}{9x-1}\right):\left(1-\frac{3\sqrt{x}-2}{3\sqrt{x}+1}\right)\)
\(B=\left(\frac{x-3\sqrt{x}}{x-9}-1\right):\left(\frac{9-x}{x+\sqrt{x}-6}+\frac{\sqrt{x}-3}{\sqrt{x}-2}-\frac{\sqrt{x}-2}{\sqrt{x}+3}\right)\)
giải phương trình:
a/\(\frac{\sqrt{x}-2}{\sqrt{x}-5}=\frac{\sqrt{x}-4}{\sqrt{x}-6}\)
b/\(\sqrt{18x+9}-\sqrt{8x+4}+\frac{1}{3}\sqrt{2x+1}=4\)
c/\(\sqrt{4x-8}-\frac{1}{2}\sqrt{x-2}+\sqrt{9x-18}=9\)
Giải các pt sau:
1, \(\sqrt{x^2+x+1}=2x+\sqrt{x^2-x+1}\)
2, \(2x^2+2x+6=2x\sqrt{x^2-x+1}+4\sqrt{3x+1}\)
3, \(\left(\sqrt{x+3}-\sqrt{x}\right)\left(1+\sqrt{x^2+3x}\right)=3\)
4, \(\sqrt{2x^2-1}+\sqrt{x^2-3x-2}=\sqrt{2x^2-2x+3}+\sqrt{x^2-x+2}\)
5, \(13\sqrt{x-1}+9\sqrt{x+1}=16x\)
