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2x+1/5 =3/2x-1
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2(1-2x)-5=3(x+2)
=>\(2-4x-5=3x+6\)
=>\(-4x-3=3x+6\)
=>\(-7x=9\)
=>\(x=-\dfrac{9}{7}\)
a) 2x - 3 = x + 1/2
<=> 2x - 3 = 1/2x + 1/2
<=> 2x - 3 - 1/2x = 1/2
<=> 3/2x - 3 = 1/2
<=> 3/2x = 1/2 + 3
<=> 3/2x = 7/2
<=> x = 7/2 : 3/2
<=> x = 7/3
=> x = 7/3
\(a,2x-3=x+\frac{1}{2}\)
\(2x-3=\frac{1}{2}x+\frac{1}{2}\)
\(2x-3-\frac{1}{2}x=\frac{1}{2}\)
\(\frac{3}{2}x-3=\frac{1}{2}\)
\(\frac{3}{2}x=\frac{1}{2}+3\)
\(\frac{3}{2}x=\frac{7}{2}\)
\(x=\frac{7}{2}:\frac{3}{2}\)
\(x=\frac{14}{6}=\frac{7}{3}\)
\(\)B làm tương tự
Bài làm:
Ta có: \(\left(2x-5\right)\left(x^3+1\right)-\left(2x-5\right)\left(x+1\right)=0\)
\(\Leftrightarrow\left(2x-5\right)\left(x+1\right)\left(x^2-x+1\right)-\left(2x-5\right)\left(x+1\right)=0\)
\(\Leftrightarrow\left(2x-5\right)\left(x+1\right)\left(x^2-x-1\right)=0\)
\(\Leftrightarrow x\left(x-1\right)\left(x+1\right)\left(2x-5\right)=0\)
GPT này ra ta được: \(x\in\left\{-1;0;1;\frac{5}{2}\right\}\)
\(\left(2x-5\right)\left(x^3+1\right)-\left(2x-5\right)\left(x+1\right)=0\)
\(\Leftrightarrow2x^4+2x-5x^3-5-\left(2x^2+2x-5x-5\right)=0\)
\(\Leftrightarrow2x^4+2x-5x^3-5-2x^2-2x+5x+5=0\)
\(\Leftrightarrow2x^4+5x-5x^3-2x^2=0\)
\(\Leftrightarrow x\left(2x^3+5-5x^2-2x\right)=0\)
\(\Leftrightarrow x=0;\frac{5}{2};\pm1\)
|2x+1|=3-(-5)
|2x+1|=8
=>2x+1=8
hoặc 2x+1=-8
=>x=7/2
hoặc x=-9/2
vậy x=7/2 hoặc x=-9/2
giải dùm bn thoi chứ h mk k cần vì mk có kinh nghiem ke hứa nhieu
k bao gio giu loi hua
2x -3x +5x = 3/3 - 4/4 + 12/5
4x = 1-1 + 12/5
x = 3/5
\(\Leftrightarrow2x\left(x+5\right)-3\left(x-2\right)=7x+1\)
\(\Leftrightarrow2x^2+10x-3x+6-7x-1=0\)
\(\Leftrightarrow2x^2+5=0\)(vô lý)
ĐKXĐ:\(\left\{{}\begin{matrix}x\ne2\\x\ne-5\end{matrix}\right.\)
\(\dfrac{2x}{x-2}-\dfrac{3}{x+5}=\dfrac{7x+1}{x^2+3x-10}\\ \Leftrightarrow\dfrac{2x\left(x+5\right)}{\left(x+5\right)\left(x-2\right)}-\dfrac{3\left(x-2\right)}{\left(x+5\right)\left(x-2\right)}=\dfrac{7x+1}{x^2-2x+5x-10}\\ \Leftrightarrow\dfrac{2x^2+10x}{\left(x+5\right)\left(x-2\right)}-\dfrac{3x-6}{\left(x+5\right)\left(x-2\right)}=\dfrac{7x+1}{x\left(x-2\right)+5\left(x-2\right)}\\ \Leftrightarrow\dfrac{2x^2+10x}{\left(x+5\right)\left(x-2\right)}-\dfrac{3x-6}{\left(x+5\right)\left(x-2\right)}-\dfrac{7x+1}{\left(x+5\right)\left(x-2\right)}=0\)
\(\Leftrightarrow\dfrac{2x^2+10x-3x+6-7x-1}{\left(x+5\right)\left(x-2\right)}=0\\ \Leftrightarrow\dfrac{2x^2+5}{\left(x+5\right)\left(x-2\right)}=0\\ \Rightarrow2x^2+5=0\left(vô.lí\right)\)
Vậy pt vô nghiệm