rut gon bt ;
a) \(\left(\sqrt{27}-2\sqrt{17}+\sqrt{7}\right)\cdot\sqrt{7}+7\sqrt{8}\)
b) \(\sqrt{3-2\sqrt{2}}+\sqrt{3+2\sqrt{2}}\)
c) \(9\sqrt{2}-4\sqrt{8}-\sqrt{50}+2\sqrt{32}\)
d) \(\sqrt{3-2\sqrt{2}}-\sqrt{6+4\sqrt{2}}\)
NK
Những câu hỏi liên quan
rut gon bt ( a +2) ^ 2 – ( a + 2)(a – 2)
Ta có: \(\left(a+2\right)^2-\left(a+2\right)\left(a-2\right)\)
\(=\left(a+2\right)\left(a+2-a+2\right)\)
\(=\left(a+2\right)\cdot4=4a+8\)
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Rut gon BT sau : A=a.a-b)-b.(a-b)
Rut gon bt 2n+3+2n+2-2n+1+2n n la so mu nha
Ý bạn là
\(2^n+3+2^{^{ }n}+2-2^{^{ }n}+1+2^n\)
Giải :
\(A=2^n+3+2^n+2-2^n+1+2^n\)
\(A=\left(2^n+2^n-2^n+2^n\right)+3+1\)
\(A=3\times2^n+3+1\)
\(A=3\times2^n+4\)
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Rut gon bt P=12(5^2+1)(5^4+1)(5^8+1)(5^16+1)
P=2.(5^2-1).(5^2+1).(5^4+1).(5^8+1).(5^16+1)
=2.(5^4-1).(5^4+1).(5^8+1).(5^16+1)
= 2.(5^8-1).(5^8+1).(5^16+1)
= 2.(5^16-1).(5^16+1)
= 2.(5^32-1)
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1)P= 12(5^2+1)(5^4+1)(5^8+1)(5^16+1)
=> 2P = 24(5^2+1)(5^4+1)(5^8+1)(5^16+1)
=(5^2-1)(5^2+1)(5^4+1)(5^8+1)(5^16+1)
=(5^4-1)(5^4+1)(5^8+1)(5^16+1)
=(5^8-1)(5^8+1)(5^16+1)
=(5^16-1)(5^16+1)
=5^32-1
=> P = (5^32-1)/2
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rut gon
1/x-1-x/1-x^3*x^2+x+1/x+1):(2x+1/x^2+x+1)
toi rut gon dc
x^2+x+1/x^2-1
nhung ko tinh dc gtri nguyen cua x de bt tren co gtri nguyen
Cho A=x/(√x -1) - (2x - √x)/(x-√x)
rut gon bt A
tinh gia tri cua bt A tai x=3+2√2
Rut gon bt C=\(\dfrac{\sqrt{4x+4+\dfrac{1}{x}}}{\sqrt{x}.\left|2x^2-x-1\right|}\)
\(C=\dfrac{\sqrt{\dfrac{4x^2+4x+1}{x}}}{\sqrt{x}\cdot\left|2x^2-x-1\right|}=\dfrac{\left|2x+1\right|}{\sqrt{x}}\cdot\dfrac{1}{\sqrt{x}\cdot\left|\left(x-1\right)\left(2x+1\right)\right|}\)
\(=\dfrac{1}{x\left|x-1\right|}\)
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rut gon cac bt
(x2-xy+y2)(x2+xy+y2)
cho bt A \(\frac{x+2}{x\sqrt{x}-1}+\frac{\sqrt{x}+1}{x+\sqrt{x}+1}-\frac{1}{\sqrt{x}-1}\)
a) rut gon bt A
b) cm A < 1/3
cho bt D=[1/x-1 -2/x3-x2+x-1 :(1-x/x2+1)
a) rut gon bt D
b) chung minh rang D>0 voi moi gia tri cua x de D co nghia