Giải pt: \(\frac{2}{3x^2-4x+1}+\frac{13}{3x^2+2x+1}=\frac{6}{x}\)
Những câu hỏi liên quan
giải pt \(\frac{x^2+x+1}{x^2+2x+1}+\frac{x^2+3x+1}{x^2+4x+1}=\frac{5}{6}\)
a) x4+x3+2x2+x+1=(x4+x3+x2)+(x2+x+1)=x2(x2+x+1)+(x2+x+1)=(x2+x+1)(x2+1)
b)a3+b3+c3-3abc=a3+3ab(a+b)+b3+c3 -(3ab(a+b)+3abc)=(a+b)3+c3-3ab(a+b+c)
=(a+b+c)((a+b)2-(a+b)c+c2)-3ab(a+b+c)=(a+b+c)(a2+2ab+b2-ac-ab+c2-3ab)=(a+b+c)(a2+b2+c2-ab-ac-bc)
c)Đặt x-y=a;y-z=b;z-x=c
a+b+c=x-y-z+z-x=o
đưa về như bài b
d)nhóm 2 hạng tử đầu lại và 2hangj tử sau lại để 2 hạng tử sau ở trong ngoặc sau đó áp dụng hằng đẳng thức dề tính sau đó dặt nhân tử chung
e)x2(y-z)+y2(z-x)+z2(x-y)=x2(y-z)-y2((y-z)+(x-y))+z2(x-y)
=x2(y-z)-y2(y-z)-y2(x-y)+z2(x-y)=(y-z)(x2-y2)-(x-y)(y2-z2)=(y-z)(x2-2y2+xy+xz+yz)
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22 tháng 10 2019 lúc 17:12
Giải pt
a) 2x^2+sqrt{x^2-5x-6}10x+15
b) 5sqrt{3x^2-4x-2}-6x^2+8x+70
c) x^2+sqrt{2x^2+4x+3}6-2x
d) 2sqrt{frac{3x-1}{x}}frac{x}{3x-1}+1
e) sqrt{frac{24x-4}{x}}frac{x}{6x-1}+1
f) sqrt{frac{2x-1}{x}}+1+sqrt{frac{x}{2x-1}}frac{3x}{2x-1}
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Giải pt
a) \(2x^2+\sqrt{x^2-5x-6}=10x+15\)
b) \(5\sqrt{3x^2-4x-2}-6x^2+8x+7=0\)
c) \(x^2+\sqrt{2x^2+4x+3}=6-2x\)
d) \(2\sqrt{\frac{3x-1}{x}}=\frac{x}{3x-1}+1\)
e) \(\sqrt{\frac{24x-4}{x}}=\frac{x}{6x-1}+1\)
f) \(\sqrt{\frac{2x-1}{x}}+1+\sqrt{\frac{x}{2x-1}}=\frac{3x}{2x-1}\)
a/ ĐKXĐ: ...
\(\Leftrightarrow2\left(x^2-5x-6\right)+\sqrt{x^2-5x-6}-3=0\)
Đặt \(\sqrt{x^2-5x-6}=a\ge0\)
\(2a^2+a-3=0\Rightarrow\left[{}\begin{matrix}a=1\\a=-\frac{3}{2}\left(l\right)\end{matrix}\right.\)
\(\Rightarrow\sqrt{x^2-5x-6}=1\Leftrightarrow x^2-5x-7=0\)
b/ ĐKXĐ: ...
\(\Leftrightarrow5\sqrt{3x^2-4x-2}-2\left(3x^2-4x-2\right)+3=0\)
Đặt \(\sqrt{3x^2-4x-2}=a\ge0\)
\(-2a^2+5a+3=0\) \(\Rightarrow\left[{}\begin{matrix}a=3\\a=-\frac{1}{2}\left(l\right)\end{matrix}\right.\)
\(\Rightarrow\sqrt{3x^2-4x-2}=3\Leftrightarrow3x^2-4x-11=0\)
c/ \(\Leftrightarrow x^2+2x-6+\sqrt{2x^2+4x+3}=0\)
Đặt \(\sqrt{2x^2+4x+3}=a>0\Rightarrow x^2+2x=\frac{a^2-3}{2}\)
\(\frac{a^2-3}{2}-6+a=0\Leftrightarrow a^2+2a-15=0\Rightarrow\left[{}\begin{matrix}x=3\\x=-5\left(l\right)\end{matrix}\right.\)
\(\Rightarrow\sqrt{2x^2+4x+3}=3\Leftrightarrow2x^2+4x-6=0\)
d/ ĐKXĐ: ...
Đặt \(\sqrt{\frac{3x-1}{x}}=a>0\)
\(2a=\frac{1}{a^2}+1\Leftrightarrow2a^3-a^2-1=0\)
\(\Leftrightarrow\left(a-1\right)\left(2a^2+a+1\right)=0\)
\(\Rightarrow a=1\Rightarrow\sqrt{\frac{3x-1}{x}}=1\Leftrightarrow3x-1=x\)
e/ĐKXĐ: ...
\(\Leftrightarrow2\sqrt{\frac{6x-1}{x}}=\frac{x}{6x-1}+1\)
Đặt \(\sqrt{\frac{6x-1}{x}}=a>0\)
\(2a=\frac{1}{a^2}+1\Leftrightarrow2a^3-a^2-1=0\Leftrightarrow\left(a-1\right)\left(2a^2+a+1\right)=0\)
\(\Rightarrow a=1\Rightarrow\sqrt{\frac{6x-1}{x}}=1\Rightarrow6x-1=x\)
f/ ĐKXĐ: ...
Đặt \(\sqrt{\frac{x}{2x-1}}=a>0\)
\(\frac{1}{a}+1+a=3a^2\)
\(\Leftrightarrow3a^3-a^2-a-1=0\)
\(\Leftrightarrow\left(a-1\right)\left(3a^2+2a+1\right)=0\)
\(\Leftrightarrow a=1\Rightarrow\sqrt{\frac{x}{2x-1}}=1\Rightarrow x=2x-1\)
Giải pt: \(\frac{2x+1}{x^2}+\frac{x^2}{2\left(3x^2+4x+2\right)}=-\frac{1}{2}\)
\(x\ne0\)
\(\frac{2x+1}{x^2}+1+\frac{x^2}{2\left(3x^2+4x+2\right)}-\frac{1}{2}=0\)
\(\Leftrightarrow\frac{x^2+2x+1}{x^2}-\frac{2\left(x^2+2x+1\right)}{2\left(3x^2+4x+2\right)}=0\)
\(\Leftrightarrow\left(x+1\right)^2\left(\frac{1}{x^2}-\frac{1}{3x^2+4x+2}\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x+1=0\\x^2=3x^2+4x+2\end{matrix}\right.\) \(\Rightarrow x=-1\)
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\(\frac{x-1}{13}+\frac{2x-13}{15}=\frac{3x-15}{27}+\frac{4x-27}{29}\) Giải Pt trên
giải pt
\(\frac{2x-1}{x-1}\) + \(\frac{3x-2}{x-2}\) = \(\frac{x^2+4x+5}{x^2-3x+2}\) + 4
ĐKXĐ: \(x\ne1;x\ne2\)
\(\frac{2x-1}{x-1}+\frac{3x-2}{x-2}=\frac{x^2+4x+5}{x^2-3x+2}+4\\ \Leftrightarrow\frac{2x^2-5x+2}{\left(x-1\right)\left(x-2\right)}+\frac{3x^2-5x+2}{\left(x-1\right)\left(x-2\right)}=\frac{x^2+4x+5}{\left(x-1\right)\left(x-2\right)}+\frac{4x^2-12x+8}{\left(x-1\right)\left(x-2\right)}\\ \Rightarrow2x^2-5x+2+3x^2-5x+2=x^2+4x+5+4x^2-12x+8\\ \Leftrightarrow2x^2+3x^2-x^2-4x^2-5x-5x-4x+12x=5-2-2\\ \Leftrightarrow-2x=1\\ \Leftrightarrow x=\frac{-1}{2}\left(tm\right)\)Vậy tập nghiệm của phương trình là: \(S=\left\{-\frac{1}{2}\right\}\)
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ĐKXĐ: x∉{1;2}
Ta có: \(\frac{2x-1}{x-1}+\frac{3x-2}{x-2}=\frac{x^2+4x+5}{x^2-3x+2}+4\)
\(\Leftrightarrow\frac{\left(2x-1\right)\left(x-2\right)}{\left(x-1\right)\left(x-2\right)}+\frac{\left(3x-2\right)\left(x-1\right)}{\left(x-2\right)\left(x-1\right)}=\frac{x^2+4x+5}{\left(x-1\right)\left(x-2\right)}+\frac{4\left(x^2-3x+2\right)}{\left(x-1\right)\left(x-2\right)}\)
Suy ra: \(\left(2x-1\right)\left(x-2\right)+\left(3x-2\right)\left(x-1\right)=x^2+4x+5+4\left(x^2-3x+2\right)\)
\(\Leftrightarrow2x^2-4x-x+2+3x^2-3x-2x+2=x^2+4x+5+4x^2-12x+8\)
\(\Leftrightarrow5x^2-10x+4=5x^2-8x+13\)
\(\Leftrightarrow5x^2-10x+4-5x^2+8x-13=0\)
\(\Leftrightarrow-2x-9=0\)
\(\Leftrightarrow-2x=9\)
hay \(x=\frac{-9}{2}\)(tm)
Vậy: \(S=\left\{-\frac{9}{2}\right\}\)
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giải PT:\(\frac{12x}{x^2+4x+12}-\frac{3x}{x^2+2x+2}=1\)
để ý rằng nếu x là nghiệm thì x\(\ne\)0 nên ta chia cả tử số và mẫu số của vế trái cho x thì ta thu được \(\frac{12}{x+4+\frac{2}{x}}-\frac{3}{x+2+\frac{2}{x}}=1\)đặt \(t=x+\frac{2}{x}+2\)thì phương trình trở thành
\(\frac{12}{t+2}-\frac{3}{t}=1\Leftrightarrow12t-3t-6=t^2+2t\Leftrightarrow t^2-7t+6=0\Leftrightarrow\orbr{\begin{cases}t=1\\t=6\end{cases}}\)
với t=1 ta có \(x+\frac{2}{x}+2=1\Leftrightarrow t^2+t+2=0\)(vô nghiệm)
với t=6 ta có \(x+\frac{x}{2}+2=6\Leftrightarrow x^2-4x+2=0\Leftrightarrow x=2\pm\sqrt{2}\)
Bài 1. Giải các phương trình sau
1) frac{3x+2}{2}-frac{3x+1}{6}frac{5}{3}-2x
2) frac{x-3}{5}6-frac{1-2x}{3}
3) 2left(x+frac{3}{5}right)5-left(frac{13}{5}+xright)
4) frac{2x+3}{3}frac{5-4x}{2}
5) frac{5x+3}{12}frac{1+2x}{9}
6) x-frac{x+1}{3}frac{2x+1}{5}
7) frac{3left(x-3right)}{4}+frac{4x-10,5}{10}frac{3left(x+1right)}{5}+6
8) frac{2left(3x+1right)+1}{4}-5frac{2
left(3x-1right)}{5}-frac{3x+2}{10}
9) frac{x+1}{3}+frac{3left(2x+1right)}{4}frac{2x+3left(x+1right)}{6}+frac{7+12x}{12}
10...
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Bài 1. Giải các phương trình sau
1) \(\frac{3x+2}{2}-\frac{3x+1}{6}=\frac{5}{3}-2x\)
2) \(\frac{x-3}{5}=6-\frac{1-2x}{3}\)
3) \(2\left(x+\frac{3}{5}\right)=5-\left(\frac{13}{5}+x\right)\)
4) \(\frac{2x+3}{3}=\frac{5-4x}{2}\)
5) \(\frac{5x+3}{12}=\frac{1+2x}{9}\)
6) \(x-\frac{x+1}{3}=\frac{2x+1}{5}\)
7) \(\frac{3\left(x-3\right)}{4}+\frac{4x-10,5}{10}=\frac{3\left(x+1\right)}{5}+6\)
8) \(\frac{2\left(3x+1\right)+1}{4}-5=\frac{2 \left(3x-1\right)}{5}-\frac{3x+2}{10}\)
9) \(\frac{x+1}{3}+\frac{3\left(2x+1\right)}{4}=\frac{2x+3\left(x+1\right)}{6}+\frac{7+12x}{12}\)
10) \(\frac{2x-1}{3}-\frac{5x+2}{7}=x+13\)
bài 1:giải các pt sau:
a/frac{1-x}{x+1}+3frac{2x+3}{x+1}
b/frac{left(x+2right)^2}{2x-3}-1frac{x^2+10}{2x-3}
c/frac{1}{x+1}-frac{5}{x-2}frac{15}{left(x+1right)left(2-xright)}
d/frac{1-6x}{x-2}+frac{9x+4}{x+2}frac{xleft(3x-2right)+1}{x^2-4}
e/frac{12}{1-9x^2}frac{1-3x}{1+3x}-frac{1+3x}{1-3x}
ffrac{x+4}{x^2-3x+2}+frac{x+1}{x^2-4x+3}frac{2x+5}{x^2-4x+3}
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bài 1:giải các pt sau:
a/\(\frac{1-x}{x+1}\)+3=\(\frac{2x+3}{x+1}\)
b/\(\frac{\left(x+2\right)^2}{2x-3}-1=\frac{x^2+10}{2x-3}\)
c/\(\frac{1}{x+1}-\frac{5}{x-2}=\frac{15}{\left(x+1\right)\left(2-x\right)}\)
d/\(\frac{1-6x}{x-2}+\frac{9x+4}{x+2}=\frac{x\left(3x-2\right)+1}{x^2-4}\)
e/\(\frac{12}{1-9x^2}=\frac{1-3x}{1+3x}-\frac{1+3x}{1-3x}\)
f\(\frac{x+4}{x^2-3x+2}+\frac{x+1}{x^2-4x+3}=\frac{2x+5}{x^2-4x+3}\)
GPT
\(\frac{3}{3x^2-4x+1}+\frac{13}{3x^2+2x+1}=\frac{6}{x}\)