Ta có: \(\left(a-3\right)^2-\sqrt{0.2}\cdot\sqrt{180a^2}\)
\(=\left(a-3\right)^2-\sqrt{36a^2}\)
\(=a^2-6a+9-6a\)
\(=a^2-12a+9\)
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Bài 4: Liên hệ giữa phép chia và phép khai phương
Các câu hỏi tương tự
A\(=\)\((3\sqrt{8}+2\sqrt{50}-4\sqrt{72})\)\(➗\)\(8\sqrt{2}\)
B\(=\)\((-4\sqrt{20}+5\sqrt{500}-3\sqrt{45})\div5 \)
C\(=(\dfrac{\sqrt{3}+1}{\sqrt{3}-1}-\dfrac{\sqrt{3}-1}{\sqrt{3}+1})\div\sqrt{48}\)
Tính : a)dfrac{3sqrt{2}-2sqrt{3}}{sqrt{3}-sqrt{2}}-dfrac{3}{3-sqrt{6}}
b)left(2sqrt{2}-sqrt{3}right)^2-2sqrt{3}left(sqrt{3}-2sqrt{2}right)
c) left(dfrac{1}{3-sqrt{5}}-dfrac{1}{3+sqrt{5}}right):dfrac{5-sqrt{5}}{sqrt{5}-1}
d)left(3-dfrac{a-2sqrt{a}}{sqrt{a}-2}right)left(3+dfrac{sqrt{ab}-3sqrt{a}}{sqrt{b}-3}right)b ne 9 với age0 , bge0, ane 4
Mọi người ai biết giúp tớ với ạ !! Mai tớ phải nộp rồi !! Cảm ơn mọi người trước !
Đọc tiếp
Tính : a)\(\dfrac{3\sqrt{2}-2\sqrt{3}}{\sqrt{3}-\sqrt{2}}-\dfrac{3}{3-\sqrt{6}}\)
b)\(\left(2\sqrt{2}-\sqrt{3}\right)^2-2\sqrt{3}\left(\sqrt{3}-2\sqrt{2}\right)\)
c) \(\left(\dfrac{1}{3-\sqrt{5}}-\dfrac{1}{3+\sqrt{5}}\right):\dfrac{5-\sqrt{5}}{\sqrt{5}-1}\)
d)\(\left(3-\dfrac{a-2\sqrt{a}}{\sqrt{a}-2}\right)\left(3+\dfrac{\sqrt{ab}-3\sqrt{a}}{\sqrt{b}-3}\right)\)b \(\ne\) 9 với a\(\ge\)0 , b\(\ge\)0, a\(\ne\) 4
Mọi người ai biết giúp tớ với ạ !! Mai tớ phải nộp rồi !! Cảm ơn mọi người trước !
bài 1 rút gọn
a \(A=\left(3-\sqrt{5}\right)\sqrt{3+\sqrt{5}}+\left(3+\sqrt{5}\right)\sqrt{3-\sqrt{5}}\)
b\(B=\left(5+\sqrt{21}\right)\left(\sqrt{14}-\sqrt{6}\right)\sqrt{5-\sqrt{21}}\)
c\(C=\sqrt{4+\sqrt{7}}-\sqrt{4-\sqrt{7}}\) d\(D=\sqrt{2+\sqrt{3}}+\sqrt{14-5\sqrt{3}}+\sqrt{2}\)
Rút gọn
a) ( 2 - \(\frac{a-3.\sqrt{a}}{\sqrt{a}-3}\) ) . (2 - \(\frac{5-\sqrt{a}-\sqrt{a}.b}{\sqrt{b}-5}\))
b) \(\frac{9-a}{\sqrt{a}+3}\)- \(\frac{9-6.\sqrt{a}+a}{\sqrt{a}-3}\)
Làm tính chia:
a,(\(3\sqrt{x^2y}\)-\(4\sqrt{xy^2}\)+5xy):\(\sqrt{xy}\)
b,(\(\sqrt{a^3b}\)+\(\sqrt{ab}\)-\(3\sqrt{ab^3}\)):\(\sqrt{ab}\)
Rut gon
a) ( 2- \(\frac{a-3.\sqrt{a}}{\sqrt{a}-3}\)) . ( 2- \(\frac{5.\sqrt{a}+\sqrt{a}.b}{\sqrt{b}-5}\))
b) \(\frac{9-a}{\sqrt{a}+3}\)- \(\frac{9-6.\sqrt{a}+a}{\sqrt{a}-3}\)- 6
Rut gon
a) ( 2- \(\frac{a-3.\sqrt{a}}{\sqrt{a}-3}\)) . ( 2- \(\frac{5.\sqrt{a}+\sqrt{a}.b}{\sqrt{b}-5}\))
b) \(\frac{9-a}{\sqrt{a}+3}\)- \(\frac{9-6.\sqrt{a}+a}{\sqrt{a}-3}\)- 6
tính
1\(\left(5\sqrt{3}+3\sqrt{5}\right):\sqrt{15}\)
2\(\left(2\sqrt{3}-3\right):5\sqrt{3}\)
3\(\left(2\sqrt{18}-3\sqrt{8}+6\right):\sqrt{2}\)
4\(\sqrt{27\left(1-\sqrt{3}\right)^2}:3\sqrt{15}\)
5\(\dfrac{a-\sqrt{b}}{\sqrt{b}}:\dfrac{\sqrt{b}}{a+\sqrt{b}}\)
1. Tìm x để bt có nghĩa
Adfrac{sqrt{2x+3}}{sqrt{x-3}}
Bsqrt{dfrac{2x+3}{x-3}}
Csqrt{-dfrac{5}{x+2}}
Dsqrt{-x}+dfrac{1}{x+3}
2. Rút gọn bt
Asqrt{dfrac{a+sqrt{a^2-1}}{2}}-sqrt{dfrac{a-sqrt{a^2-1}}{2}};left(a1right)
Bsqrt{dfrac{a+sqrt{a^2-1}}{2}}-sqrt{dfrac{a-sqrt{a^2-b}}{2}};left(agesqrt{b};bge0right)
Cleft(1+dfrac{a+sqrt{a}}{a+1}right)left(1-dfrac{a-sqrt{a}}{sqrt{a}+1}right);left(age0,ane1right)
Ddfrac{x^2+sqrt{x}}{x-sqrt{x}+1}-dfrac{2x+sqrt{x}}{sqrt{x}};left(x0right)
Đọc tiếp
1. Tìm x để bt có nghĩa
A=\(\dfrac{\sqrt{2x+3}}{\sqrt{x-3}}\)
B=\(\sqrt{\dfrac{2x+3}{x-3}}\)
C=\(\sqrt{-\dfrac{5}{x+2}}\)
D=\(\sqrt{-x}+\dfrac{1}{x+3}\)
2. Rút gọn bt
A=\(\sqrt{\dfrac{a+\sqrt{a^2-1}}{2}}-\sqrt{\dfrac{a-\sqrt{a^2-1}}{2}};\left(a>1\right)\)
B=\(\sqrt{\dfrac{a+\sqrt{a^2-1}}{2}}-\sqrt{\dfrac{a-\sqrt{a^2-b}}{2}};\left(a\ge\sqrt{b};b\ge0\right)\)
C=\(\left(1+\dfrac{a+\sqrt{a}}{a+1}\right)\left(1-\dfrac{a-\sqrt{a}}{\sqrt{a}+1}\right);\left(a\ge0,a\ne1\right)\)
D=\(\dfrac{x^2+\sqrt{x}}{x-\sqrt{x}+1}-\dfrac{2x+\sqrt{x}}{\sqrt{x}};\left(x>0\right)\)