Rút gọn:
\(A=\left(\frac{4x\sqrt{x}+3x+9}{x+5\sqrt{x}+6}-\frac{3-\sqrt{x}}{2+\sqrt{x}}\right)\div\left(\frac{\sqrt{x}}{3+\sqrt{x}}-\frac{3+4\sqrt{x}}{x+5\sqrt{x}+6}\right)\)
\(B=\left(x-\sqrt{x}-2\right)\left(\dfrac{3}{\sqrt{x}-2}-\dfrac{4-\sqrt{x}}{x-2\sqrt{x}}\right)\)
1.Cho bốn số dương a, b, c, d.
Chứng minh rằng
: \(\sqrt{ab}+\sqrt{cd}< =\sqrt{\left(a+d\right)}\left(b+c\right)\)
2. Cho a2+b2 =<2
Chứng minh rằng:
\(a\sqrt{3a\left(a+2b\right)}+b\sqrt{3b\left(b+2a\right)}=< 6\)
rút gọn
C=\(\left(4+\sqrt{15}\right)\left(\sqrt{10}-\sqrt{6}\right)\left(\sqrt{4-\sqrt{15}}\right)\)
Cho các số thực không âm a,b,ca,b,c thoả mãn a+b+c=1a+b+c=1. Chứng minh rằng :
\(\sqrt{a+\frac{\left(b-c\right)^2}{4}}+\sqrt{b+\frac{\left(c-a\right)^2}{4}}+\sqrt{c+\frac{\left(a-b\right)^2}{4}}\le\sqrt{3}+\left(1-\frac{\sqrt{3}}{2}\right)\left(\text{|
}a-b\text{|
}\right)+\text{|
}b-c\text{|
}+\text{|
}c-a\text{|
}.\)
Tính GTBT chứa căn:
a,\(\left(\sqrt{14}-3\sqrt{2}\right)^2\)+\(6\sqrt{28}\)
b,\(\left(\sqrt{6}-\sqrt{5}\right)^2\)-\(2\sqrt{120}\)
c,\(\left(2\sqrt{3}-3\sqrt{2}\right)^2+2\sqrt{6}+3\sqrt{24}\)
Giải phương trình: \(\frac{\left(x^6+3x^4\sqrt{x^2-x+1}\right)\left(3+x-x^2\right)}{4\left(2+\sqrt{x^2-x+1}\right)\left(x^2-x+1\right)}=\sqrt{x^2-x+1}\left(2-\sqrt{x^2-x+1}\right)\)
Giải phương trình: \(\frac{\left(x^6+3x^4\sqrt{x^2-x+1}\right)\left(3+x-x^2\right)}{4\left(2+\sqrt{x^2-x+1}\right)\left(x^2-x+1\right)}=\sqrt{x^2-x+1}\left(2-\sqrt{x^2-x+1}\right)\)
Chứng minh :\(\left(\sqrt[3]{3+2.\sqrt{2}}+\sqrt[3]{3-2.\sqrt{2}}\right)^8>3^6\)
Rút gọn :\(A=\frac{\sqrt{6+2.\left(\sqrt{6}+\sqrt{3}+\sqrt{2}\right)}-\sqrt{6-2.\left(\sqrt{6}-\sqrt{3}-\sqrt{2}\right)}}{\sqrt{2}}\)