cho phuong trinh \(\frac{5x-m}{6}-1=\frac{2x+m}{5}-\frac{m}{10}+\frac{7\left(5-x\right)}{28}\)

a)Tinh x khi m=11

b)Tim so nguyen m sao cho -5<x<1

Giai cac phuong trinh sau:

a)/x-1/+/2x+1/=4

b)/x/-/x-3/+/x+4/=6

c) /x+3/+/x-5/=8

Tim x,biet

\(\left(2x-1\right)^{2012}=\left(2x-1\right)^{2010}\)

Cm: voi moi so tu nhien \(n\ge1\)

\(\dfrac{1}{2^2}+\dfrac{1}{4^2}+\dfrac{1}{6^2}+...+\dfrac{1}{\left(2n\right)^2}< \dfrac{1}{2}\)

cho hinh binh hanh ABCD. Goi G diem nam tren canh CD,K la diem nam tren canh CB sao cho CB=2DG va 2BK=3CK.Goi giao diem cua BD voi AG va AK lan luot la E va F . Tinh do dai cac doan thang DE,EF,FB.Biet BD=24cm

Cho tam giac ABC co AB=24cm,AC=30cm,BC=36cm.Cac duong trung tuyen AM va BN cat nhau tai G.Goi O la giao diem cua cac duong phan giac AD va BE.Tinh AE,EC,BD,DC,OG?

Cho a,b,c thoa man \(\dfrac{1}{a}+\dfrac{1}{b}+\dfrac{1}{c}=\dfrac{1}{a+b+c}\)

Tinh GT cua bieu thuc A=\(\left(a^3+b^3\right)\left(b^3+c^3\right)\left(c^3+a^3\right)\)

cho 3 so thoa man \(\dfrac{1}{x}+\dfrac{1}{y}+\dfrac{1}{z}=0\)

CM: \(\dfrac{1}{x^2+2yz}+\dfrac{1}{y^2+2zx}+\dfrac{1}{z^2+2xy}=0\)

Rut gon bieu thuc

A=(x+1)\(\left(x^2+1\right)\left(x^4+1\right)...\left(x^{256}+1\right)+1\)

Chia da thuc f(x) cho da thuc (x+1) co so du la 5. Chia da thuc f(x) cho da thuc \(x^2+1\) co so du la 2x+3. Tim so du trong phep chia da thuc ?