giai giup mik vs a \(\dfrac{1}{1+\sqrt[3]{2}+\sqrt[3]{4}}\)
\(\dfrac{1}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+2\right)}\) \(\dfrac{1}{\left(\sqrt{X}-1\right)\left(3-\sqrt{X}\right)}\)
GIUP MIK VS NHA,CẢM ƠN
`1/((sqrtx-1)(sqrtx+2))-1/((sqrtx-1)(3-sqrtx))`
`=1/((sqrtx-1)(sqrtx+2))+1/((sqrtx-1)(sqrtx-3))`
`=(sqrtx-3+sqrtx+2)/((sqrtx-1)(sqrtx+2)(sqrtx-3))`
`=(2sqrtx-1)/((sqrtx-1)(sqrtx+2)(sqrtx-3))`
\(\dfrac{-2}{\sqrt{3}-1}\) \(\dfrac{\sqrt{5}}{\sqrt{7}-3}\) \(\dfrac{3\sqrt{3}-2}{1-2\sqrt{3}}\) \(\dfrac{14}{\sqrt{10}+\sqrt{3}}\) Trục căn thức ở mẫu:
giúp mik vs
\(\dfrac{-2}{\sqrt{3}-1}=\dfrac{-2\left(\sqrt{3}+1\right)}{2}=-\sqrt{3}-1\\ \dfrac{\sqrt{5}}{\sqrt{7}-3}=\dfrac{-\sqrt{5}\left(\sqrt{7}+3\right)}{2}\\ \dfrac{3\sqrt{3}-2}{1-2\sqrt{3}}=\dfrac{\left(3\sqrt{3}-2\right)\left(1+2\sqrt{3}\right)}{-11}=\dfrac{\sqrt{3}-16}{11}\\ \dfrac{14}{\sqrt{10}+\sqrt{3}}=\dfrac{14\left(\sqrt{10}-\sqrt{3}\right)}{7}=2\sqrt{10}-2\sqrt{3}\)
1) Tính giá trị biểu thức:
a)A=\(\sqrt{4+2\sqrt{3}}\)
b) B=\(\dfrac{1}{2-\sqrt{3}}+\dfrac{1}{2+\sqrt{3}}\)
2) Giai phương trình: \(\sqrt{4x-12}+\sqrt{x-3}-\dfrac{1}{3}\sqrt{9x-27}=8\)
3)Tìm x: 2x2-4=8
`a)A=\sqrt{4+2sqrt3}`
`=\sqrt{3+2sqrt3+1}`
`=sqrt{(sqrt3+1)^2}`
`=sqrt3+1`
`B)1/(2-sqrt3)+1/(2+sqrt3)`
`=(2+sqrt3)/(4-3)+(2-sqrt3)/(4-3)`
`=2+sqrt3+2-sqrt3`
`=4`
`\sqrt{4x-12}+sqrtx{x-3}-1/3sqrt{9x-27}=8`
`đk:x>=3`
`pt<=>2sqrt{x-3}+sqrt{x-3}-sqrt{x-3}=8`
`<=>2sqrt{x-3}=8`
`<=>sqrt{x-3}=4`
`<=>x-3=16`
`<=>x=19`
Vậy `S={19}`
`a)A=\sqrt{4+2sqrt3}`
`=\sqrt{3+2sqrt3+1}`
`=sqrt{(sqrt3+1)^2}`
`=sqrt3+1`
`B)1/(2-sqrt3)+1/(2+sqrt3)`
`=(2+sqrt3)/(4-3)+(2-sqrt3)/(4-3)`
`=2+sqrt3+2-sqrt3`
`=4`
`\sqrt{4x-12}+sqrt{x-3}-1/3sqrt{9x-27}=8`
`đk:x>=3`
`pt<=>2sqrt{x-3}+sqrt{x-3}-sqrt{x-3}=8`
`<=>2sqrt{x-3}=8`
`<=>sqrt{x-3}=4`
`<=>x-3=16`
`<=>x=19`
Vậy `S={19}`
\(\left(\dfrac{\sqrt{x}}{\sqrt{x}-1}-\dfrac{1}{\sqrt{x}\left(\sqrt{x}-1\right)}\right)\)Giup mik vs nha mngg
mik đg vội
a)\(\sqrt{16}\)+\(\sqrt{225}\).\(\sqrt{9}\)
b)\(\sqrt{\dfrac{10000}{400}}\)+\(\sqrt{\left(-3\right)^2}\).\(\sqrt{6^4}\)
giup mik ai nhanh mik se tick cho
a) \(\sqrt{16}+\sqrt{225}.\sqrt{9}=4+15.3=4+45=49\)
b) \(\sqrt{\dfrac{10000}{400}}+\sqrt{\left(-3\right)^2}.\sqrt{6^4}=\dfrac{100}{20}+\sqrt{9}.\sqrt{36^2}=5+3.36=5+108=113\)
b. \(\sqrt{\dfrac{10000}{400}}+\sqrt{\left(-3\right)^2}.\sqrt{6^4}=\dfrac{100}{20}+3.6^2=5+3.36=5+108=113\)
a)\(\sqrt{\dfrac{10000}{\sqrt{400}}}\)+\(\sqrt{\left(3\right)^2}\).\(\sqrt{6^4}\)
b)\(\sqrt{1600}\):\(\sqrt{25}\)+\(\sqrt{49}\).\(\sqrt{16}\)-\(\sqrt{\left(-10\right)^2}\)
giup mik ai nhanh mik se tick cho nhe
giai phuong trinh
\(\sqrt{x}-5+\dfrac{1}{3}\sqrt{9x}-45=\dfrac{1}{5}\sqrt{25x}-125=6\)
giup minh voi
Sửa đề: \(\sqrt{x-5}+\dfrac{1}{3}\sqrt{9x-45}=\dfrac{1}{5}\sqrt{25x-125}+6\)
\(\Leftrightarrow\sqrt{x-5}+\dfrac{1}{3}\cdot3\cdot\sqrt{x-5}-\dfrac{1}{5}\cdot5\sqrt{x-5}=6\)
\(\Leftrightarrow\sqrt{x-5}=6\)
=>x-5=36
hay x=41
Cho biểu thức P=(\(\dfrac{a-3\sqrt{a}+2}{3a-7\sqrt{a}+2}\)-\(\dfrac{\sqrt{a}-3}{3a-8\sqrt{a}-3}\)+\(\dfrac{8\sqrt{a}}{9a-1}\)) : (1-\(\dfrac{2\sqrt{a}-a+1}{3\sqrt{a}+1}\))
Tìm giá trị nghuyên lớn nhất của a để P> \(\dfrac{3}{|1-3\sqrt{5}|}\)
Giup mk vs
DAT P = Q:R \(Q=\dfrac{\left(\sqrt{a}-1\right)\left(\sqrt{a}-2\right)}{\left(\sqrt{a}-2\right)\left(3\sqrt{a}-1\right)}-\dfrac{\sqrt{a}-3}{\left(\sqrt{a}-3\right)\left(3\sqrt{a}-1\right)}+\dfrac{8\sqrt{a}}{\left(3\sqrt{a}-1\right)\left(3\sqrt{a}+1\right)}\)
\(=\dfrac{\sqrt{a}-1}{3\sqrt{a}-1}-\dfrac{1}{3\sqrt{a}+1}+\dfrac{8\sqrt{a}}{\left(3\sqrt{a}-1\right)\left(3\sqrt{a}+1\right)}\)
\(=\dfrac{3\sqrt{a}\left(\sqrt{a}+1\right)}{\left(3\sqrt{a}-1\right)\left(3\sqrt{a}+1\right)}\)
\(R=1-\dfrac{2\sqrt{a}-a+1}{3\sqrt{a}+1}=\dfrac{a+\sqrt{a}}{3\sqrt{a}+1}=\dfrac{\sqrt{a}\left(\sqrt{a}+1\right)}{3\sqrt{a}+1}\)
\(\Rightarrow P=Q:R=\dfrac{3\sqrt{a}\left(\sqrt{a}+1\right)}{\left(3\sqrt{a}-1\right)\left(3\sqrt{a}+1\right)}\times\dfrac{3\sqrt{a}+1}{\sqrt{a}\left(\sqrt{a}+1\right)}\)
\(P=\dfrac{3}{3\sqrt{a}-1}\)
\(P>\dfrac{3}{\left|1-3\sqrt{5}\right|}\Leftrightarrow\dfrac{3}{3\sqrt{a}-1}>\dfrac{3}{3\sqrt{5-1}}\)
\(3\sqrt{a}-1< 3\sqrt{5}-1\)
\(\Rightarrow0\le\sqrt{a}\le\sqrt{5}\)
\(a=\) 0 ;1 ;2 ;3 ;4
a lớn nhất \(\Rightarrow a\) = 4
Mong các bạn giải nhanh giúp mik vs mai mik thi r
1.rút gọn : A=(2-\(\sqrt{2}\))(-5\(\sqrt{2}\))-(3\(\sqrt{2}\)-5)\(^2\)
2.a, rút gọn:B=(\(\dfrac{1}{\sqrt{a}-1}-\dfrac{1}{\sqrt{a}}\)):(\(\dfrac{\sqrt{a}+1}{\sqrt{a}-2}-\dfrac{\sqrt{a}+2}{\sqrt{a}-1}\))
b, Tìm a để B>0
3.-rút gọn C=(\(\dfrac{\sqrt{x}}{3+\sqrt{x}}+\dfrac{x+9}{9-x}\)):(\(\dfrac{3\sqrt{x}+1}{x-3\sqrt{x}}-\dfrac{1}{\sqrt{x}}\))
-Tìm x để C<-1
Câu 3:
\(C=\dfrac{3\sqrt{x}-x+x+9}{9-x}:\dfrac{3\sqrt{x}+1-\sqrt{x}+3}{\sqrt{x}\left(\sqrt{x}-3\right)}\)
\(=\dfrac{-3\left(\sqrt{x}+3\right)}{x-9}\cdot\dfrac{\sqrt{x}\left(\sqrt{x}-3\right)}{2\sqrt{x}+4}\)
\(=\dfrac{-3\sqrt{x}}{2\sqrt{x}+4}\)
Để C<-1 thì C+1<0
=>-3 căn x+2 căn x+4<0
=>-căn x<-4
=>x>16