Đưa thừa số ra ngoài dấu căn: \(\frac{1}{x-y}\sqrt{x^4\left(x^2+y^2-2xy\right)}\) (x<y)
đưa thừa số ra ngoài dấu căn
\(\frac{2xy^2}{3ab}\sqrt{\frac{9a^3b^4}{8xy^3}}\)với a,b,x,y>0
\(\frac{2xy^2}{3ab}\sqrt{\frac{9a^3b^4}{8xy^3}}=\frac{2xy^2}{3ab}\frac{3\sqrt{a^2.a}\sqrt{\left(b^2\right)^2}}{2\sqrt{2xy^2.y}}\)
\(=\frac{2xy^2}{3ab}\frac{3a\sqrt{a}b^2}{2y\sqrt{2xy}}=\frac{6xy^2ab^2\sqrt{a}}{6aby\sqrt{2xy}}=\frac{bxy\sqrt{a}}{\sqrt{2xy}}\)
\(=\frac{bxy\sqrt{2axy}}{2xy}=\frac{b\sqrt{2axy}}{2}\)
\(\sqrt{48.45}\) Đưa thừa số ra ngoài dấu căn:
\(\sqrt{225.17}\)
\(\sqrt{a^3b^7}với\) \(a\ge0;b\ge0\)
\(\sqrt{x^5\left(x-3\right)^2}\) với \(x>0\)
\(\sqrt{48\cdot45}=12\sqrt{15}\\ \sqrt{225\cdot17}=15\sqrt{17}\\ \sqrt{a^3b^7}=\left|ab^3\right|\sqrt{ab}=ab^3\sqrt{ab}\\ \sqrt{x^5\left(x-3\right)^2}=\left|x^2\left(x-3\right)\right|\sqrt{x}=x^2\left(x-3\right)\sqrt{x}\)
\(\sqrt{48\cdot45}=4\sqrt{3}\cdot3\sqrt{5}=12\sqrt{15}\)
\(\sqrt{225\cdot17}=15\sqrt{17}\)
Đưa thừa số ra ngoài dấu căn
a) \(\sqrt{25.96}\)
b) \(\sqrt{21.75.14}\)
c) \(y^2.\sqrt{x^6.y^8}\)
d) \(a^3.\sqrt{a^5.\left(a-3\right)^2}\)
e)\(\left(x-6\right).\sqrt{\frac{x}{36-x^2}}\)
a) \(\sqrt{25\cdot96}=\sqrt{5^2\cdot2^5\cdot3}=\sqrt{5^2\cdot\left(2^2\right)^2\cdot2\cdot3}\)
\(=20\sqrt{6}\)
b) \(\sqrt{21\cdot75\cdot14}=\sqrt{2\cdot3^2\cdot5^2\cdot7^2}=105\sqrt{2}\)
c) \(y^2\sqrt{x^6\cdot y^8}=\sqrt{x^6\cdot y^4\cdot y^8}=\sqrt{\left(x^3\right)^2\cdot\left(y^6\right)^2}=x^3\cdot y^6\)
hì,giúp bn đc phần a thôi nha!!!
\(a,\sqrt{25.96}=\sqrt{25.16.6}=\sqrt{25}.\sqrt{16}.\sqrt{6}=5.4.\sqrt{6}=20\sqrt{6}\)
=.= hok tốt!!!
d) \(a^3.\sqrt{a^5.\left(a-3\right)^2}=a^3.\sqrt{a^5}.\sqrt{\left(a-3\right)^2}=a^3.\sqrt{a^5}.\left(a-3\right)\)
1. Chứng minh rằng: \(\frac{2x^2+1}{\sqrt{4x^2+1}}\ge1\)
2. Tìm GTLN: A=\(\frac{1}{x-\sqrt{x}+1}\left(x>0\right)\)
3. Đưa thừa số ra ngoài dấu căn
B= \(\frac{1}{2x-1}\sqrt{5\left(1-4x+4x^2\right)}\)
Đưa thừa số ra ngoài dấu căn:
a) $\sqrt{28 x^{4} y^{2}}$ với $y \leq 0$;
b) $\sqrt{63 a^{2} b^{4}}$ với $a \geq 0$;
c) $\sqrt{147(a-1)^{3}}$;
d) $\sqrt{192(y+2)^{5}}$.
a, -2x^2y căn 7
b, ab^2 căn 63
c, a-1 căn 147a-147
d, y+2 nhân căn [192 nhân (y+2)^3]
a)-2x²y√7
b) 3ab²√7
c) 7(a-1)√3(a-1)
d) 8(y+2)²√3(y+2)
Đưa thừa số vào trong dấu căn:
a) \(-\frac{a}{b}\sqrt{\frac{b}{a}}\left(a>0,b>0\right)\)
b)\(\frac{1}{2x-1}\sqrt{5-20x+20x^2}\) (x> \(\frac{1}{2}\)
c) \(\left(x-5\right)\sqrt{\frac{3}{25-x^2}}\)
d) \(\frac{x}{x-y}\sqrt{\frac{x-y}{x}}\)
a)\(=-\sqrt{\left(\frac{a}{b}\right)^2\cdot\frac{b}{a}}\)
\(=-\sqrt{\frac{a^2}{b^2}\cdot\frac{b}{a}}\)
\(=-\sqrt{\frac{a}{b}}\)
b) \(=\sqrt{\left(\frac{1}{2x-1}\right)^2\cdot5\left(4x^2-4x+1\right)}\)
\(=\sqrt{\frac{5}{\left(2x-1\right)^2}\cdot\left(2x-1\right)^2}\)
\(=\sqrt{5}\)
c)\(=\sqrt{\left(x-5\right)^2\cdot\frac{-3}{\left(x-5\right)\left(x+5\right)}}\)
\(=\sqrt{\frac{-3\left(x-5\right)}{x+5}}\)
\(=\sqrt{\frac{15-3x}{x+5}}\)
2. đưa thừa số ra ngoài dấu căn:
a,\(\sqrt{108}\)
b,\(\sqrt{28a^4b^2}\)(b>0)
c,\(\sqrt{72a^2b^4}\)( a<0)
d,\(\sqrt{\frac{39\left(x+y\right)^2}{2}}\)( x>0, y>0 và x≠y)
a/ đưa các thừa số ra ngoài dấu căn :
1/\(\sqrt{27x^2}(x>0)\)
2/\(\sqrt{8xy^2}(x\ge0;y\le0)\)
b/ đưa thừa số vào trong dấu căn :
1/\(x\sqrt{13}(x\ge0)\)
2/\(x\sqrt{-15x}(x< 0)\)
3/\(x\sqrt{2}(x\le0)\)
a) \(\sqrt{27x^2}=\sqrt{3.\left(3x\right)^2}=\left|3x\right|.\sqrt{3}=3x\sqrt{3}\left(x>0\right)\)
b) \(\sqrt{8xy^2}=\left|y\right|.2\sqrt{2x}=-2y\sqrt{2x}\left(x\ge0,y\le0\right)\)
1) \(x\sqrt{13}=\sqrt{13x^2}\left(x\ge0\right)\)
2) \(x\sqrt{-15x}=-\left|x\right|\sqrt{15x}=-\sqrt{15x^3}\left(x< 0\right)\)
3) \(x\sqrt{2}=-\left|x\right|\sqrt{2}=-\sqrt{2x^2}\left(x\le0\right)\)
đưa thừa số ra ngoài dấu căn
a) √128(x-y)^2
b) √150(4x^2-4x+1)
c) √x^3-6x^2+12x-8
a) \(\sqrt{128\left(x-y\right)^2}\)
\(=\sqrt{8^2\cdot2\left(x-y\right)^2}\)
\(=\left|8\left(x-y\right)\right|\sqrt{2}\)
\(=8\left|\left(x-y\right)\right|\sqrt{2}\)
b) \(\sqrt{150\left(4x^2-4x+1\right)}\)
\(=\sqrt{5^2\cdot6\left(2x-1\right)^2}\)
\(=\left|5\left(2x-1\right)\right|\sqrt{6}\)
\(=5\left|2x-1\right|\sqrt{6}\)
c) \(\sqrt{x^3-6x^2+12x-8}\)
\(=\sqrt{\left(x-2\right)^3}\)
\(=\sqrt{\left(x-2\right)^2\left(x-2\right)}\)
\(=\left|x-2\right|\sqrt{x-2}\)
a: \(=\sqrt{64\cdot2\cdot\left(x-y\right)^2}=8\sqrt{2}\cdot\left|x-y\right|\)
b; \(=\sqrt{25\cdot6\left(2x-1\right)^2}=5\sqrt{6}\cdot\left|2x-1\right|\)
c: \(=\sqrt{\left(x-2\right)^3}=\left|x-2\right|\cdot\sqrt{x-2}\)