\(a.\sqrt{4a^2}voi\:a\ge0\)
\(b.\sqrt{0,16\left(x-2\right)^2}voi\:x\ge2\)
\(c.\sqrt{25.\left(3-a\right)^2}+3\)
\(d.\frac{1}{2\left(x-5\right)}\sqrt{36.\left(x-5\right)^2}-5\:voi\:x\ne5\)
Những câu hỏi liên quan
B1 Rút gọn
a)\(\sqrt{6+2\sqrt{5}}-\sqrt{29-12\sqrt{2}}\)
b)\(\frac{2}{x^2y^2}\sqrt{\frac{3\left(x+y\right)^2}{2}}\left(x\ge0;y\ge0;x\ne y\right)\)
c)\(\frac{2}{2a-1}\sqrt{5a^2\left(1-4a+4a^2\right)}\left(a>\frac{1}{2}\right)\)
B2 giải pt
\(\sqrt{3-x}+3\sqrt{12-4x}-5\sqrt{48-16x}=-39\)
HELP ME!!!!
Chứng minh các đẳng thức saua) left(frac{2sqrt{6}-sqrt{3}}{2sqrt{2}-1}+frac{5+2sqrt{5}}{2+sqrt{5}}right)left(sqrt{5}-sqrt{3}right)b) frac{a-b}{b^2}sqrt{frac{a^2b^4}{a^2-2ab+b^2}}-a(Với ba0c)left(sqrt{a}+frac{1-asqrt{a}}{1-sqrt{a}}right)left(frac{1-sqrt{a}}{1-a}right)^21với age0,a khác 1d) left(frac{3sqrt{5}-sqrt{15}}{sqrt{27}-3}+frac{2sqrt{5}}{sqrt{3}}right)40sqrt{15}600e) left(1+frac{x+sqrt{x}}{sqrt{x}+1}right)left(1-frac{x-sqrt{x}}{sqrt{x}-1}right)1-xvới xge0;xne1
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Chứng minh các đẳng thức sau
a) \(\left(\frac{2\sqrt{6}-\sqrt{3}}{2\sqrt{2}-1}+\frac{5+2\sqrt{5}}{2+\sqrt{5}}\right)\left(\sqrt{5}-\sqrt{3}\right)\)
b) \(\frac{a-b}{b^2}\sqrt{\frac{a^2b^4}{a^2-2ab+b^2}}=-a\)(Với b<a<0
c)\(\left(\sqrt{a}+\frac{1-a\sqrt{a}}{1-\sqrt{a}}\right)\left(\frac{1-\sqrt{a}}{1-a}\right)^2=1\)với a\(\ge0\),a khác 1
d) \(\left(\frac{3\sqrt{5}-\sqrt{15}}{\sqrt{27}-3}+\frac{2\sqrt{5}}{\sqrt{3}}\right)40\sqrt{15}=600\)
e) \(\left(1+\frac{x+\sqrt{x}}{\sqrt{x}+1}\right)\left(1-\frac{x-\sqrt{x}}{\sqrt{x}-1}\right)=1-x\)với x\(\ge0;x\ne1\)
Chứng minh đẳng thức:
a) dfrac{xsqrt{x}+ysqrt{y}}{sqrt{x}+sqrt{y}}-left(sqrt{x}-sqrt{y}right)^2sqrt{xy}left(xge0,yge0,x^2+y^2ne0right)
b) left(dfrac{1}{a-sqrt{a}}+dfrac{1}{sqrt{a}-1}right):dfrac{sqrt{a}+1}{a-2sqrt{a}+1}left(age0,ane1right)
c) sqrt{x+2sqrt{x-2}-1}left(sqrt{x-2}-1right):left(sqrt{x}-sqrt{3}right)sqrt{x}+sqrt{3}left(xge2,xne3right)
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Chứng minh đẳng thức:
a) \(\dfrac{x\sqrt{x}+y\sqrt{y}}{\sqrt{x}+\sqrt{y}}-\left(\sqrt{x}-\sqrt{y}\right)^2=\sqrt{xy}\left(x\ge0,y\ge0,x^2+y^2\ne0\right)\)
b) \(\left(\dfrac{1}{a-\sqrt{a}}+\dfrac{1}{\sqrt{a}-1}\right):\dfrac{\sqrt{a}+1}{a-2\sqrt{a}+1}\left(a\ge0,a\ne1\right)\)
c) \(\sqrt{x+2\sqrt{x-2}-1}\left(\sqrt{x-2}-1\right):\left(\sqrt{x}-\sqrt{3}\right)=\sqrt{x}+\sqrt{3}\left(x\ge2,x\ne3\right)\)
a: \(=x-\sqrt{xy}+y-x+2\sqrt{xy}-y=\sqrt{xy}\)
b: \(=\dfrac{1+\sqrt{a}}{a-\sqrt{a}}\cdot\dfrac{\left(\sqrt{a}-1\right)^2}{\sqrt{a}+1}=\dfrac{\sqrt{a}-1}{\sqrt{a}}\)
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a)3sqrt{40sqrt{12}}+4sqrt{sqrt{75}}-5sqrt{5sqrt{48}}b)sqrt{8sqrt{3}}+3sqrt{20sqrt{3}}-2sqrt{45sqrt{3}}c)left(sqrt{x}-1right).left(x+sqrt{x}+1right)left(xge0;yge0right)d)left(sqrt{x}+1right)left(x+1-sqrt{x}right)left(xge0;yge0right)e)left(sqrt{x}+yright)left(x+y^2-ysqrt{2}right)left(xge0;yge0right)
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a)\(3\sqrt{40\sqrt{12}}+4\sqrt{\sqrt{75}}-5\)\(\sqrt{5\sqrt{48}}\)
b)\(\sqrt{8\sqrt{3}}+3\sqrt{20\sqrt{3}}-2\sqrt{45\sqrt{3}}\)
c)\(\left(\sqrt{x}-1\right).\left(x+\sqrt{x}+1\right)\left(x\ge0;y\ge0\right)\)
d)\(\left(\sqrt{x}+1\right)\left(x+1-\sqrt{x}\right)\left(x\ge0;y\ge0\right)\)
e)\(\left(\sqrt{x}+y\right)\left(x+y^2-y\sqrt{2}\right)\left(x\ge0;y\ge0\right)\)
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Rút gọn biểu thức sau
a)A= 2 - x\(\sqrt{\frac{x}{x-2}+\frac{1}{x^2-4x+4}}\left(x>2\right)\)
b) B= \(\frac{2x}{x-2}\sqrt{5\left(x-2\right)^2}+\frac{\sqrt{45x^4}}{x}\left(x\ne0;x\ne2\right)\)
c) C= \(\frac{x-25}{x+5\sqrt{x}}+\sqrt{\frac{x-2\sqrt{x}+1}{x-10\sqrt{x}+25}}\left(x>0;x\ne5\right)\)
\(A=2-x\sqrt{\frac{x\left(x-2\right)}{\left(x-2\right)^2}+\frac{1}{\left(x-2\right)^2}}=2-x\sqrt{\frac{\left(x-1\right)^2}{\left(x-2\right)^2}}\)
\(=2-x\cdot\frac{x-1}{x-2}=\frac{2x-4}{x-2}-\frac{x^2-x}{x-2}=\frac{-x^2+3x-4}{x-2}\)
\(B=\frac{2\sqrt{5}x}{x-2}\cdot\left|x-2\right|+\frac{3\sqrt{5}x^2}{x}=\frac{2\sqrt{5}x}{x-2}\cdot\left|x-2\right|+3\sqrt{5}x\)
Với 0 < x < 2 \(B=-2\sqrt{5}x+3\sqrt{5}x=\sqrt{5}x\)
Với x > 2 \(B=2\sqrt{5}x+3\sqrt{5}x=5\sqrt{5}x\)
\(C=\frac{\left(\sqrt{x}-5\right)\left(\sqrt{x}+5\right)}{\sqrt{x}\left(\sqrt{x}+5\right)}+\sqrt{\frac{\left(\sqrt{x}-1\right)^2}{\left(\sqrt{x}-5\right)^2}}=\frac{\sqrt{x}-5}{\sqrt{x}}+\left|\frac{\sqrt{x}-1}{\sqrt{x}-5}\right|\)
Với 0 < x < 1 \(C=\frac{\sqrt{x}-5}{\sqrt{x}}+\frac{\sqrt{x}-1}{\sqrt{x}-5}=\frac{x-10\sqrt{x}+25}{x\left(\sqrt{x}-5\right)}+\frac{x-\sqrt{x}}{x\left(\sqrt{x}-5\right)}=\frac{2x-11\sqrt{x}+25}{x\left(\sqrt{x}-5\right)}\)
Với 1 < x < 5 \(C=\frac{\sqrt{x}-5}{\sqrt{x}}-\frac{\sqrt{x}-1}{\sqrt{x}-5}=\frac{x-10\sqrt{x}+25}{x\left(\sqrt{x}-5\right)}-\frac{x-\sqrt{x}}{x\left(\sqrt{x}-5\right)}=\frac{-9\sqrt{x}+25}{x\left(\sqrt{x}-5\right)}\)
Với x > 5 \(C=\frac{\sqrt{x}-5}{\sqrt{x}}+\frac{\sqrt{x}-1}{\sqrt{x}-5}=\frac{x-10\sqrt{x}+25}{x\left(\sqrt{x}-5\right)}+\frac{x-\sqrt{x}}{x\left(\sqrt{x}-5\right)}=\frac{2x-11\sqrt{x}+25}{x\left(\sqrt{x}-5\right)}\)
Bài 2: Xét sự tương đương của các cặp BPT sau
a, 4x-6+frac{1}{x-2}ge2+frac{1}{x-2} và 4x-8ge0
b, 3x-2+frac{1}{x-3}ge1+frac{1}{x-3} và 3x-3ge0
c, x+4ge0 và left(x-1right)^2left(x+4right)0
d,left(x^2-4x+5right)left(x-5right)0 và x-50
e, x-12ge0 và left(x-2right)^2ge0
f, sqrt{left(x-1right)left(x-2right)}ge x và sqrt{x-1}.sqrt{x-2}ge x
Bài 3. Giải bất phương trình
a, |5x – 3| < 2
b, left|3x-2right|ge6
c, left|2x-1right|le x+2
d, left|3x+7right|2x+3
e, sqrt{x-3}gesqrt{3-x}
f, sqrt{x-...
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Bài 2: Xét sự tương đương của các cặp BPT sau
a, \(4x-6+\frac{1}{x-2}\ge2+\frac{1}{x-2}\) và \(4x-8\ge0\)
b, \(3x-2+\frac{1}{x-3}\ge1+\frac{1}{x-3}\) và \(3x-3\ge0\)
c, \(x+4\ge0\) và \(\left(x-1\right)^2\left(x+4\right)>0\)
d,\(\left(x^2-4x+5\right)\left(x-5\right)>0\) và \(x-5>0\)
e, \(x-12\ge0\) và \(\left(x-2\right)^2\ge0\)
f, \(\sqrt{\left(x-1\right)\left(x-2\right)}\ge x\) và \(\sqrt{x-1}.\sqrt{x-2}\ge x\)
Bài 3. Giải bất phương trình
a, \(|5x – 3| < 2\)
b, \(\left|3x-2\right|\ge6\)
c, \(\left|2x-1\right|\le x+2\)
d, \(\left|3x+7\right|>2x+3\)
e, \(\sqrt{x-3}\ge\sqrt{3-x}\)
f, \(\sqrt{x-1}< 3+\sqrt{x-1}\)
g, \(\frac{x-2}{\sqrt{x-4}}\ge\frac{4}{\sqrt{x-4}}\)
h, \(\left(x+5\right)\sqrt{\left(x-3\right)\left(x^2-10x+25\right)}>0\)
mình sửa lại bài 3 ý a, \(\left|5x-3\right|< 2\)
Rút gọna)3sqrt{40sqrt{12}}+4sqrt{sqrt{75}}-5sqrt{5sqrt{48}}b)sqrt{8sqrt{3}}+3sqrt{20sqrt{3}}-2sqrt{45sqrt{3}}c)left(sqrt{x}-1right).left(x+sqrt{x}+1right)left(xge0;yge0right)d)left(sqrt{x}+1right)left(x+1-sqrt{x}right)left(xge0;yge0right)e)left(sqrt{x}+yright).left(x+y^2-ysqrt{2}right)left(xge0;yge0right)
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Rút gọn
a)\(3\sqrt{40\sqrt{12}}+4\sqrt{\sqrt{75}}-5\)\(\sqrt{5\sqrt{48}}\)
b)\(\sqrt{8\sqrt{3}}+3\sqrt{20\sqrt{3}}-2\sqrt{45\sqrt{3}}\)
c)\(\left(\sqrt{x}-1\right).\left(x+\sqrt{x}+1\right)\left(x\ge0;y\ge0\right)\)
d)\(\left(\sqrt{x}+1\right)\left(x+1-\sqrt{x}\right)\left(x\ge0;y\ge0\right)\)
e)\(\left(\sqrt{x}+y\right).\left(x+y^2-y\sqrt{2}\right)\left(x\ge0;y\ge0\right)\)
Rút gọn biểu thức:
a) Aleft(frac{3x-3sqrt{x}-3}{x+sqrt{x}-2}+frac{1}{sqrt{x}-1}-frac{1}{sqrt{x}+2}right):frac{1}{sqrt{x}+2}left(xge0,xne1right)
b) Bfrac{xsqrt{x}-3}{x-2sqrt{x}-3}-frac{2left(sqrt{x-3}right)}{sqrt{x}+1}+frac{sqrt{x}+3}{3-sqrt{x}}left(x0,xne9right)
c) Cfrac{2sqrt{x}-9}{x-5+6}-frac{sqrt{x}+3}{sqrt{x}-2}-frac{2sqrt{x}+1}{3-sqrt{x}}left(xge0,xne4,xne9right)
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Rút gọn biểu thức:
a) \(A=\left(\frac{3x-3\sqrt{x}-3}{x+\sqrt{x}-2}+\frac{1}{\sqrt{x}-1}-\frac{1}{\sqrt{x}+2}\right):\frac{1}{\sqrt{x}+2}\left(x\ge0,x\ne1\right)\)
b) \(B=\frac{x\sqrt{x}-3}{x-2\sqrt{x}-3}-\frac{2\left(\sqrt{x-3}\right)}{\sqrt{x}+1}+\frac{\sqrt{x}+3}{3-\sqrt{x}}\left(x>0,x\ne9\right)\)
c) \(C=\frac{2\sqrt{x}-9}{x-5+6}-\frac{\sqrt{x}+3}{\sqrt{x}-2}-\frac{2\sqrt{x}+1}{3-\sqrt{x}}\left(x\ge0,x\ne4,x\ne9\right)\)
a. \(\sqrt{x}\left(\sqrt{x}-3\right)-5\left(\sqrt{x}+3\right)\)
b. \(3\left(2+\sqrt{x}\right)+\left(\sqrt{x}+3\right)\left(2-\sqrt{x}\right)\)
c. \(\left(\sqrt{x}+3\right)\left(\sqrt{x}-3\right)-5\left(\sqrt{x}-1\right)\)
d. \(3\left(\sqrt{x}-2\right)-\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)\)
a: Ta có: \(\sqrt{x}\left(\sqrt{x}-3\right)-5\left(\sqrt{x}+3\right)\)
\(=x-3\sqrt{x}-5\sqrt{x}-15\)
\(=x-8\sqrt{x}-15\)
b: Ta có: \(3\left(\sqrt{x}+2\right)+\left(\sqrt{x}+3\right)\left(2-\sqrt{x}\right)\)
\(=3\sqrt{x}+6+2\sqrt{x}-x+6-3\sqrt{x}\)
\(=-x+2\sqrt{x}+12\)
c: Ta có: \(\left(\sqrt{x}+3\right)\left(\sqrt{x}-3\right)-5\left(\sqrt{x}-1\right)\)
\(=x-9-5\sqrt{x}+5\)
\(=x-5\sqrt{x}-4\)
d: Ta có: \(3\left(\sqrt{x}-2\right)-\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)\)
\(=3\sqrt{x}-6-x+1\)
\(=-x+3\sqrt{x}-5\)
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