Cho a, b, c thuộc R sao cho a.b.c = 2008.
CMR : \(\frac{2008a}{ab+2008a+2008}+\frac{b}{bc+b+2008}+\frac{c}{ca+c+1}=1\)
cho a+b+c=0; ab+bc+ca=0. tinh gia tri cua bieu thuc A=(a-1)^2008+b^2009+(c+1)^2010
giải phương trình: \(\frac{x+1}{2010}+\frac{x+2}{2009}+\frac{x+3}{2008}+...+\frac{x+2009}{2}+\frac{x+2010}{1}\)\(=\left(-2010\right)\)
\(\frac{x+1}{2010}+\frac{x+2}{2009}+\frac{x+3}{2008}+...+\frac{x+2010}{1}=\left(-2010\right)\)
\(\Rightarrow\left(\frac{x+1}{2010}+1\right)+\left(\frac{x+2}{2009}+1\right)+...+\left(\frac{x+2010}{1}+1\right)=-2010+2010\)
\(\Rightarrow\frac{x+2011}{2010}+\frac{x+2011}{2009}+...+\frac{x+2011}{1}=0\)
\(\Rightarrow\left(x+2011\right)\left(1+\frac{1}{2}+...+\frac{1}{2009}+\frac{1}{2010}\right)=0\)
\(\Rightarrow x+2011=0\Leftrightarrow x=-2011\)
cách bạn giải bài này là gì vậy ?
a) \(\frac{\left(2007-x\right)^2+\left(2007-x\right)\left(x-2008\right)+\left(x-2008\right)^2}{\left(2007-x\right)^2-\left(2007-x\right)\left(x-2008\right)+\left(x-2008\right)^2}\) = \(\frac{19}{49}\)
b) Tìm m để PT sau có nghiệm duy nhất:
\(\frac{2m-1}{x-1}\) = m - 2 (m là tham số)
Tìm x, biết:
\(\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2008}\right).x=\frac{2009}{1}+\frac{2010}{2}+\frac{2011}{3}+...+\frac{4016}{2008}-2008\)
Giải phương trình:
\(\frac{\left(2007-x\right)^2+\left(2007-x\right)\left(x-2008\right)+\left(x-2008\right)^2}{\left(2007-x\right)^2+\left(2007-x\right)\left(2008-x\right)+\left(x-2008\right)^2}=\frac{19}{49}\)
Bạn nào giải được trước 8h30 mk sẽ hậu tạ 200k
mk giải cho mà saI CÓ đc tiền k
Cho abc= 2008
CM: \(\frac{2008a}{ab+2008a+2008}\) +\(\frac{b}{bc+b+2008}\) +\(\frac{c}{ac+c+1}\) = 1
suy ra: (a2bc/ab+a2bc+abc) +(b/bc+b+abc)+(c/ac+c+1) (chịu khó đọc nhé! tại mình không biết ấn dấu gạch ngang)
=[a2bc/ab.(1+ac+c)] + [b/b.(c+1+ac)] + (c/ac+c+1)
=(ac/1+ac+c)+(1/1+ac+c)+(c/1+ac+c)
=(ac+1+c)/(1+ac+c)
=1
Vậy ........
ĐÚNG MÀ!!!NHỚ TICK CHO MÌNH NHA!!!
Giải phương trình (tìm x):
a)\(\frac{2-x}{2007}-1=\frac{1-x}{2008}-\frac{x}{2009}\)
b) \(\left(12x+7\right)^2\left(3x+2\right)\left(2x+1\right)=3\)
a)\(\frac{2-x}{2007}-1=\frac{1-x}{2008}-\frac{x}{2009}\)
\(\Leftrightarrow\frac{2-x}{2007}-1+2=\frac{1-x}{2008}+1-\frac{x}{2009}+1\)
\(\Leftrightarrow\frac{2-x}{2007}+\frac{2007}{2007}=\frac{1-x}{2008}+\frac{2008}{2008}-\frac{x}{2009}+\frac{2009}{2009}\)
\(\Leftrightarrow\frac{2009-x}{2007}=\frac{2009-x}{2008}-\frac{2009-x}{2009}\)
\(\Leftrightarrow\frac{2009-x}{2007}-\frac{2009-x}{2008}+\frac{2009-x}{2009}=0\)
\(\Leftrightarrow\left(2009-x\right)\left(\frac{1}{2007}-\frac{1}{2008}+\frac{1}{2009}\right)=0\)
\(\Leftrightarrow2009-x=0\).Do \(\frac{1}{2007}-\frac{1}{2008}+\frac{1}{2009}\ne0\)
\(\Leftrightarrow x=2009\)
b)\(\left(12x+7\right)^2\left(3x+2\right)\left(2x+1\right)=3\)
\(\Leftrightarrow\left(12^2x^2+2\cdot12\cdot7x+7^2\right)\left(6x^2+7x+2\right)-3=0\)
\(\Leftrightarrow\left[24\left(6x^2+7x+2\right)+1\right]\left(6x^2+7x+2\right)-3=0\)
Đặt \(t=6x^2+7x+2\) ta có:
\(\left(24t+1\right)t-3=0\)\(\Leftrightarrow12t^2+t-3=0\)
Suy ra t rồi tìm đc x
VD:
INPUT: 4
OUTPUT:
1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
- Giải phương trình: \(\frac{x-2009-2010}{2008}+\frac{x-2008-2010}{2009}+\frac{x-2008-2009}{2010}=3\)
\(\frac{x-2009-2010}{2008}+\frac{x-2008-2010}{2009}+\frac{x-2008-2009}{2010}=3\)
\(\Leftrightarrow\frac{x-2008-2009-2010}{2008}+\frac{x-2008-2009-2010}{2009}+\frac{x-2008-2009-2010}{2010}=0\)
\(\Leftrightarrow\left(x-2008-2009-2010\right)\left(\frac{1}{2008}-\frac{1}{2009}-\frac{1}{2010}\right)=0\)
\(\Leftrightarrow x-6027=0\Leftrightarrow x=6027\)
