Chung minh bat dang thuc sau: \(\frac{x^2}{y^2}\)+\(\frac{y^2}{x^2}\)+4>=3(\(\frac{x}{y}\)+\(\frac{y}{x}\))
Giup mk voi . mk can gap lam. Neu thich thi ket ban voi mk nhe
2,Chung minh voi moi x nguyen duong thi phan so sau toi gian:
\(\frac{6+8x+15x^2}{13+21x+30x^2}\)
giup minh nhe minh dang can gap.
1) Phan tich da thuc sau thanh nhan tu: x2-x-2008.2009
2) Chung minh rang voi moi x,y,z ta luon co: x2+4y2+z2>=2x+12y+4z
3) Cho a-b=4. Tinh gia tri cua bieu thuc: a3-12ab-b3
cac ban lam duoc cau nao thi giup mik nha. mik dang can gap lam
tim so xyz biet \(\frac{x^2}{4}\)=\(\frac{y^2}{9}\)=\(\frac{z^2}{25}\)va x-y+xy=4
cac ban oi giup oi giup mk voi!!!
cho x>=y>=z>0.chứng minh \(\frac{x^2y}{z}+\frac{y^2z}{x}+\frac{z^2x}{y}>=x^2+y^2+z^2\)
minh dang can gap lam ai giup minh vs
cho bieu thuc P= (\(\frac{3x+\sqrt{9x}-3}{x+\sqrt{x}-2}+\frac{1}{\sqrt{x}-1}+\frac{1}{\sqrt{x}-3}\) ): \(\frac{1}{x-1}\)
a) Tim dieu kien de P co nghia, rut gon bieu thuc P.
b) Tim cac so tu nhien x de \(\frac{1}{P}\)la so tu nhien
c) Tinh gia tri cua P voi x= 4-\(2\sqrt{3}\)
Giup mk vs mk dang can gap
\(\frac{x-1}{2}=\frac{y-2}{3}=\frac{z-3}{4}vax-2y+3z=14\)
de bai la tim x, y, z biet
giup mk
mk tk
mk dag voi
\(\frac{x-1}{2}\)= \(\frac{2y-4}{6}\)=\(\frac{3z-9}{12}\)=\(\frac{x-1-2y+4+3z-9}{2-6+12}\)= \(\frac{14-1+4-9}{8}\)= 1
=> x =2+1=3
y= (6+4) : 2=5
z=(12+9) : 3=7
bài 1: cho x,y thuộc R thoả mãn x^3+y^3+3.(x^2+y^2)+4.(x+y)+4=0 với xy>0
Tìm Max M = \(\frac{1}{x}+\frac{1}{y}\)
cac ban oi giup minh. minh dang can gap.
Bai 1 : Thuc hien cac phep tinh ( tinh nhanh neu co the ) :
a) \(2\frac{1}{3}-\frac{1}{3}\)\(:\)\(\left[15\%+\left(-\frac{2}{3}+0,4.5\right)\right]\)
GIUP MK VOI NHA
MK DAG CAN GAP
AI LAM NHANH VA DUNG THI MK SE TICK CHO NHA ^ _ <
Cho bieu thuc:
\(P=\frac{x+2}{x+3}-\frac{5}{x^2+x+6}+\frac{1}{2-x}\)voi \(x\ne-3;x\ne2\)
a, Rut gon P
b, tim x de \(P=\frac{-3}{4}\)
c,tim x nguyen de P dat gia tri nguyen
(mk dang can gap ai giai dung dau tien mk tick cho)