Các câu hỏi tương tự
Cho bieu thuc \(B=\left(\frac{21}{x^2-9}-\frac{x-4}{3-x}-\frac{x-1}{3+x}\right):\left(1-\frac{1}{x+3}\right)\)
a) Rut gon B
b) Tinh gia tri bt B tai x thoa man : l 2x+1 l=5
c) Tim x de B=\(\frac{-3}{5}\)
d) Tim x de B<0
Cho ab=1 và a+b≠0. Tính
\(P=\frac{1}{\left(a+b\right)^3}\left(\frac{1}{a^3}+\frac{1}{b^3}\right)+\frac{3}{\left(a+b\right)^4}\left(\frac{1}{a^2}+\frac{1}{b^2}\right)+\frac{6}{\left(a+b\right)^5}\left(\frac{1}{a}+\frac{1}{b}\right)\)
1.tìm các nghiem nguyen cua phuong trinh: 54x^3+1=y^3
2.cho x+y=1 và xy khac 0.chung mih \(\frac{x}{y^3-1}+\frac{y}{x^3-1}+\frac{2\left(x-y\right)}{x^2y^2+3}=0\)
3.cho a,b,c la cac so thuc duong.chung minh :\(\left(\frac{a}{b+c}+\frac{b}{a+c}+\frac{c}{a+b}\right)^2+\frac{14abc}{\left(a+b\right)\left(b+c\right)\left(c+a\right)}\ge4\)
Đơn giản biểu thức E = \(\frac{1}{\left(a+b\right)^3}.\left(\frac{1}{a^3}+\frac{1}{b^3}\right)+\frac{1}{\left(a+b\right)^4}.\left(\frac{1}{a^2}+\frac{1}{b^2}\right)+\frac{1}{\left(a+b\right)^5}.\left(\frac{1}{a}+\frac{1}{b}\right)\)
Cho a,b,c la cac so nguyen duong thoa man: abc=1. CMR
\(\frac{1}{a^3\left(b+c\right)}+\frac{1}{b^3\left(c+a\right)}+\frac{1}{c^3\left(a+b\right)}\ge\frac{3}{2}\)
1)\(\frac{1}{\left(a-b\right)\left(a-c\right)}+\frac{1}{\left(b-c\right)\left(b-a\right)}+\frac{1}{\left(c-a\right)\left(c-b\right)}\)
2)\(\frac{a^2}{\left(a-b\right)\left(a-c\right)}+\frac{b^2}{\left(b-c\right)\left(b-a\right)}\frac{c^2}{\left(c-a\right)\left(c-b\right)}\)
3)\(\frac{1}{x^2+3x+2}+\frac{2x}{x^3+4x^2+4x}+\frac{1}{x^2+5x+6}\)
cau 1: tinh gia tri cua x thoa manleft(x-3right)left(x^2+3x+9right)+xleft(x+2sqrt{2}right)left(2sqrt{2}-xright)-3cau 2.tinh GTLN cua bieu thuc2x-2x^2+13cau 3. tinh gia tri cua bieu thuc frac{3^{left(x+yright)^2}}{3^{left(x-yright)^2}}voi xyfrac{1}{2}cau 4. tim GTLN cua-3x^2-6x-4cau 5. cho ham so : f(x)frac{1}{5x+9}tinh gia tri cua fleft(frac{40}{25}right)cau 6. cho hinh thang can ABCD . Day nho AB,goc D bang 64 do. tinh so do goc ngoai tai A
Đọc tiếp
cau 1: tinh gia tri cua x thoa man
\(\left(x-3\right)\left(x^2+3x+9\right)+x\left(x+2\sqrt{2}\right)\left(2\sqrt{2}-x\right)=-3\)
cau 2.tinh GTLN cua bieu thuc
\(2x-2x^2+13\)
cau 3. tinh gia tri cua bieu thuc
\(\frac{3^{\left(x+y\right)^2}}{3^{\left(x-y\right)^2}}\)voi xy=\(\frac{1}{2}\)
cau 4. tim GTLN cua
\(-3x^2-6x-4\)
cau 5. cho ham so : f(x)=\(\frac{1}{5x+9}\)
tinh gia tri cua \(f\left(\frac{40}{25}\right)\)
cau 6. cho hinh thang can ABCD . Day nho AB,goc D bang 64 do. tinh so do goc ngoai tai A
1. biết x2-2y2=xy,y\(\ne\)0,x+y\(\ne\)0. thì gia tri cua bieu thuc Q=\(\frac{x+y}{x-y}\)=
2.cho x\(\ne\)0,y\(\ne\)0 thoa man x+y=4 ;xy=2 .gia tri cua bieu thuc A=\(\frac{1}{x^3}+\frac{1}{y^3}\)la
3.gia tri cua bieu thuc A=\(\frac{81^8-1}{\left(3^4+1\right)\left(3^8+1\right)\left(3^{16}+1\right)}\)la
cho 3 so duong a;b;c thoa man a+b+c=1.tim GTNN cua:
\(p=\left(a+\frac{1}{a}\right)^2+\left(b+\frac{1}{b}\right)^2+\left(c+\frac{1}{c}\right)^2\)