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

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)