Bài 3: Liên hệ giữa phép nhân và phép khai phương
Các câu hỏi tương tự
\(\dfrac{\left(\sqrt{x}-\sqrt{y}\right)^2+4\sqrt{xy}}{\sqrt{x}+\sqrt{y}}-\dfrac{x\sqrt{y}+y\sqrt{x}}{\sqrt{xy}}\)
B1. Cho bt A = \(\left(\dfrac{x\sqrt{x}+y\sqrt{y}}{\sqrt{x}+\sqrt{y}}-\sqrt{xy}\right)-\left(\dfrac{\sqrt{x}+\sqrt{y}}{x-y}\right)^2-1\)
a) rút gọnA
b) tính g.trị của A khi x=99, y=100
B2. cho bt P=\(\dfrac{\left(\sqrt{a}+\sqrt{b}\right)-4\sqrt{ab}}{\sqrt{a}-\sqrt{b}}\)
a) tìm đk để P có nghĩa
b) rút gọn P
c) tính g.trị của P khi a=4; b=1
13 tháng 9 2021 lúc 15:18
rút gọn biểu thức
\(\dfrac{x\sqrt{y}-y\sqrt{x}}{x-\sqrt{xy}+y}\)
1) Rút gọn
a) Adfrac{x+sqrt{xy}}{y+sqrt{xy}}
b) B sqrt{dfrac{left(a-bright)^3.b^3}{c}} .sqrt{dfrac{bc^3}{left(a-bright)}} ( với a-b0, c0)
c) C(sqrt{3+2sqrt{2}} - sqrt{3-2sqrt{2}} ).(sqrt{3-2sqrt{2}} +sqrt{3+2sqrt{2}}
2) Giải phuong trình
a) sqrt{x^2-4} -sqrt{x-2} 0
b)sqrt{3x^2+12x+16} +sqrt{y^2-4y+13} 5
Đọc tiếp
1) Rút gọn
a) A=\(\dfrac{x+\sqrt{xy}}{y+\sqrt{xy}}\)
b) B= \(\sqrt{\dfrac{\left(a-b\right)^3.b^3}{c}}\) .\(\sqrt{\dfrac{bc^3}{\left(a-b\right)}}\) ( với a-b>0, c<0)
c) C=(\(\sqrt{3+2\sqrt{2}}\) - \(\sqrt{3-2\sqrt{2}}\) ).(\(\sqrt{3-2\sqrt{2}}\) +\(\sqrt{3+2\sqrt{2}}\)
2) Giải phuong trình
a) \(\sqrt{x^2-4}\) -\(\sqrt{x-2}\) =0
b)\(\sqrt{3x^2+12x+16}\) +\(\sqrt{y^2-4y+13}\) =5
B2 : Tính : a, left(sqrt{x}-3right).left(sqrt{x}+2right)b, left(sqrt{x}-sqrt{y}right).left(sqrt{x}+sqrt{y}right)c, left(sqrt{dfrac{25}{3}}-sqrt{dfrac{49}{3}}+sqrt{3}right).sqrt{3}d,left(1+sqrt{3}-sqrt{5}right).left(1+sqrt{3}+sqrt{5}right)
Đọc tiếp
B2 : Tính :
a, \(\left(\sqrt{x}-3\right)\)\(.\left(\sqrt{x}+2\right)\)
b, \(\left(\sqrt{x}-\sqrt{y}\right).\)\(\left(\sqrt{x}+\sqrt{y}\right)\)
c, \(\left(\sqrt{\dfrac{25}{3}}-\sqrt{\dfrac{49}{3}}+\sqrt{3}\right)\)\(.\sqrt{3}\)
d,\(\left(1+\sqrt{3}-\sqrt{5}\right)\)\(.\left(1+\sqrt{3}+\sqrt{5}\right)\)
Rút gọn biểu thức:
a) dfrac{xsqrt{x}+ysqrt{y}}{sqrt{x}+sqrt{y}}-left(sqrt{x}-sqrt{y}right)^2;
b) sqrt{dfrac{x-2sqrt{x}+1}{x+2sqrt{x}+1}} (xge0)
c)dfrac{x-1}{sqrt{y}-1}cdotsqrt{dfrac{left(y-2sqrt{y}+1right)^2}{left(x-1right)^4}} (xne1, yne1, y0).
Đọc tiếp
Rút gọn biểu thức:
a) \(\dfrac{x\sqrt{x}+y\sqrt{y}}{\sqrt{x}+\sqrt{y}}-\left(\sqrt{x}-\sqrt{y}\right)^2\);
b) \(\sqrt{\dfrac{x-2\sqrt{x}+1}{x+2\sqrt{x}+1}}\) (\(x\ge0\))
c)\(\dfrac{x-1}{\sqrt{y}-1}\cdot\sqrt{\dfrac{\left(y-2\sqrt{y}+1\right)^2}{\left(x-1\right)^4}}\) (\(x\ne1\), \(y\ne1\), \(y>0\)).
bài 1: tính
a) sqrt{1,2cdot27} b) sqrt{55cdot77cdot35}
c) (sqrt{3}-sqrt{2} )^2 d) (3sqrt{2}-1)*(3sqrt{2}+1)
e) (sqrt{6}+7) (sqrt{3}-sqrt{2}) i) sqrt{dfrac{1}{8}}cdotsqrt{2}cdotsqrt{125}cdotsqrt{dfrac{1}{5}}
h) sqrt{sqrt{2}-1}cdotsqrt{sqrt{2}}+1
bài 2: tính
a) sqrt{9}-sqrt{17}cdotsqrt{9}+sqrt{17}
b) 2sqrt{2}left(sqrt{3}-2right)+left(1+2sqrt{2}right)^2-2sqrt{6}
c) dfrac{sqrt{6}+sqrt{14}}{2sqrt{3}+sqrt{28}} d) dfrac{sqrt{10}+sqrt{15}}{sqrt{8}+sqrt{...
Đọc tiếp
bài 1: tính
a) \(\sqrt{1,2\cdot27}\) b) \(\sqrt{55\cdot77\cdot35}\)
c) (\(\sqrt{3}-\sqrt{2}\) )\(^2\) d) (3\(\sqrt{2}-1\))*(3\(\sqrt{2}+1\))
e) (\(\sqrt{6}+7\)) (\(\sqrt{3}-\sqrt{2}\)) i) \(\sqrt{\dfrac{1}{8}}\cdot\sqrt{2}\cdot\sqrt{125}\cdot\sqrt{\dfrac{1}{5}}\)
h) \(\sqrt{\sqrt{2}-1}\cdot\sqrt{\sqrt{2}}+1\)
bài 2: tính
a) \(\sqrt{9}-\sqrt{17}\cdot\sqrt{9}+\sqrt{17}\)
b) 2\(\sqrt{2}\left(\sqrt{3}-2\right)+\left(1+2\sqrt{2}\right)^2-2\sqrt{6}\)
c) \(\dfrac{\sqrt{6}+\sqrt{14}}{2\sqrt{3}+\sqrt{28}}\) d) \(\dfrac{\sqrt{10}+\sqrt{15}}{\sqrt{8}+\sqrt{12}}\)
e) \(\dfrac{\sqrt{15}-\sqrt{6}}{\sqrt{35}-\sqrt{14}}\) f) \(\dfrac{x+\sqrt{xy}}{9+\sqrt{xy}}\) (xy>0)
Cho bt B=\(\left(\dfrac{1}{\sqrt{x}+1}+\dfrac{1}{\sqrt{x}-1}\right)\left(\dfrac{\sqrt{x}-1}{\sqrt{x}}\right)\)
Cho E= \(\left(\dfrac{\sqrt{x}}{\sqrt{x}-1}-\dfrac{1}{x-\sqrt{x}}\right):\left(\dfrac{1}{\sqrt{x}+1}+\dfrac{2}{x-1}\right)\)
a) ĐKXĐ E
b) Rút gọn