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15 tháng 6 2022

\(\dfrac{1}{3}\)x + \(\dfrac{2}{5}\left(x-2\right)\) = 0

  \(\dfrac{1}{3}\)x + \(\dfrac{2}{5}x-\dfrac{2}{5}.2\) = 0   \(\dfrac{1}{3}\)x + \(\dfrac{2}{5}x\) - \(\dfrac{4}{5}\) = 0   \(\dfrac{1}{3}\)x + \(\dfrac{2}{5}x\) = 0 + \(\dfrac{4}{5}\)    \(\dfrac{1}{3}\)x + \(\dfrac{2}{5}x\) =  \(\dfrac{4}{5}\)  x (\(\dfrac{1}{3}+\dfrac{2}{5}\)) = \(\dfrac{4}{5}\) x. \(\dfrac{11}{15}\) = \(\dfrac{4}{5}\) x        = \(\dfrac{4}{5}\) :\(\dfrac{11}{15}\) x        =\(\dfrac{12}{11}\)      

\(\left(4-3x\right)\left(10x-5\right)=0\)

\(\Rightarrow\orbr{\begin{cases}4-3x=0\\10x-5=0\end{cases}\Rightarrow\orbr{\begin{cases}3x=4\\10x=5\end{cases}\Rightarrow}\orbr{\begin{cases}x=\frac{4}{3}\\x=\frac{1}{2}\end{cases}}}\)

\(\left(7-2x\right)\left(4+8x\right)=0\)

\(\Rightarrow\orbr{\begin{cases}7-2x=0\\4+8x=0\end{cases}\Rightarrow\orbr{\begin{cases}2x=7\\8x=-4\end{cases}\Rightarrow\orbr{\begin{cases}x=\frac{7}{2}\\x=-\frac{1}{2}\end{cases}}}}\)

rồi thực hiện đến hết ... 

Brainchild bé ngây thơ qus e , ko thực hiện đến hết như thế đc đâu :>

\(\left(x-3\right)\left(2x-1\right)=\left(2x-1\right)\left(2x+3\right)\)

\(2x^2-7x+3=4x^2+4x-3\)

\(2x^2-7x+3-4x^2-4x+3=0\)

\(-2x^2-11x+6=0\)

\(2x^2+11x-6=0\)

\(2x^2+12x-x-6=0\)

\(2x\left(x+6\right)-\left(x+6\right)=0\)

\(\left(x+6\right)\left(2x-1\right)=0\)

\(x+6=0\Leftrightarrow x=-6\)

\(2x-1=0\Leftrightarrow2x=1\Leftrightarrow x=\frac{1}{2}\)

\(3x-2x^2=0\)

\(x\left(2x-3\right)=0\)

\(x=0\)

\(2x-3=0\Leftrightarrow2x=3\Leftrightarrow x=\frac{3}{2}\)

Tự lm tiếp nha 

17 tháng 11 2021

\(1,\Leftrightarrow x\left(x-9\right)=0\Leftrightarrow\left[{}\begin{matrix}x=9\\x=0\end{matrix}\right.\\ 2,\Leftrightarrow x^2-4x-x^2=7\Leftrightarrow-4x=7\Leftrightarrow x=-\dfrac{7}{4}\\ 3,\Leftrightarrow3x+2x-10=5\Leftrightarrow5x=15\Leftrightarrow x=3\\ 4,\Leftrightarrow\left(5x-1\right)\left(5x+1\right)=0\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{5}\\x=-\dfrac{1}{5}\end{matrix}\right.\\ 5,\Leftrightarrow\left(x-2\right)\left(3x-5\right)=0\Leftrightarrow\left[{}\begin{matrix}x=2\\x=\dfrac{5}{3}\end{matrix}\right.\\ 6,\Leftrightarrow\left(x-7\right)\left(3x+4\right)=0\Leftrightarrow\left[{}\begin{matrix}x=7\\x=-\dfrac{4}{3}\end{matrix}\right.\)

\(7,\Leftrightarrow\left(2x-3\right)\left(2x+3\right)=0\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=-\dfrac{3}{2}\end{matrix}\right.\\ 8,\Leftrightarrow\left(x-4\right)\left(10x+2\right)=0\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{5}\\x=4\end{matrix}\right.\\ 9,\Leftrightarrow2x^2-5x-2x^2=0\Leftrightarrow x=0\\ 10,\Leftrightarrow2x\left(x-2\right)=0\Leftrightarrow\left[{}\begin{matrix}x=0\\x=2\end{matrix}\right.\\ 11,\Leftrightarrow\left(4x-3\right)\left(3-2x\right)=0\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{3}{4}\\x=\dfrac{3}{2}\end{matrix}\right.\\ 12,\Leftrightarrow2x^2-10x-2x^2=3\Leftrightarrow-10x=3\Leftrightarrow x=-\dfrac{3}{10}\)

17 tháng 11 2021

\(1,\Leftrightarrow x\left(x-9\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\x=9\end{matrix}\right.\\ 2,\Leftrightarrow x^2-4x-x^2=7\\ \Leftrightarrow-4x=7\\ \Leftrightarrow x=\dfrac{-7}{4}\\ 3,\Leftrightarrow3x+2x-10=5\\ \Leftrightarrow5x=15\\ \Leftrightarrow x=3\\ 4,\Leftrightarrow\left(5x-1\right)\left(5x+1\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{5}\\x=-\dfrac{1}{5}\end{matrix}\right.\)

\(5,\Leftrightarrow\left(x-2\right)\left(3x-5\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=2\\x=\dfrac{5}{3}\end{matrix}\right.\\ 6,\Leftrightarrow\left(3x+4\right)\left(x-7\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{4}{3}\\x=7\end{matrix}\right.\\ 7,\Leftrightarrow\left(2x-3\right)\left(2x+3\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=-\dfrac{3}{2}\end{matrix}\right.\)

\(8,\Leftrightarrow10x\left(x-4\right)+2\left(x-4\right)=0\\ \Leftrightarrow\left(x-4\right)\left(10x+2\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=4\\x=-\dfrac{1}{5}\end{matrix}\right.\\ 9,\Leftrightarrow2x^2-5x-2x^2=0\\ \Leftrightarrow-5x=0\\ \Leftrightarrow x=0\\ 10,\Leftrightarrow2x\left(x-2\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\x=2\end{matrix}\right.\)

\(11,\Leftrightarrow\left(2x-3\right)\left(4x-3\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=\dfrac{3}{4}\end{matrix}\right.\\ 12,\Leftrightarrow2x^2-10x-2x^2=3\\ \Leftrightarrow-10x=3\\ \Leftrightarrow x=-\dfrac{3}{10}\)

13 tháng 6 2020

Cảm ơn diễn quỳnh

13 tháng 6 2020

Mình là diễm quỳnh chứ không phải diễn quỳnh nha bạnkhocroi

1 tháng 3 2020

1. \(\Leftrightarrow\left(x-6\right)\left(x+7\right)+5\left(x-6\right)\left(3x-1\right)=0\)

\(\Leftrightarrow\left(x-6\right)\left[\left(x+7\right)+5\left(3x-1\right)\right]=0\)

\(\Leftrightarrow\left(x-6\right)\left(16x+2\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x-6=0\\16x+2=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=6\\x=-\frac{1}{8}\end{matrix}\right.\)

1 tháng 3 2020

4. \(\Leftrightarrow\left(x+5\right)^2\left(3x+2\right)^2-x^2\left(x+5\right)^2=0\)

\(\Leftrightarrow\left(x+5\right)^2\left[\left(3x+2\right)^2-x^2\right]=0\)

\(\Leftrightarrow\left(x+5\right)^2\left(2x+2\right)\left(4x+2\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}\left(x+5\right)^2=0\\2x+2=0\\4x+2=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x+5=0\\2x=-2\\4x=-2\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-5\\x=-1\\x=-\frac{1}{2}\end{matrix}\right.\)

14 tháng 2 2020

\(\left(3x+1\right)^2-x^2+8x-16=0\)

\(\Leftrightarrow\left(3x+1\right)^2-\left(x-4\right)^2=0\)

\(\Leftrightarrow\left(3x+1+x-4\right)\left(3x+1-x+4\right)=0\)

\(\Leftrightarrow\left(4x-3\right)\left(2x+5\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}4x-3=0\\2x+5=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=\frac{3}{4}\\x=\frac{-5}{2}\end{cases}}\)

14 tháng 2 2020

\(\left(3x+1\right)^2-x^2+8x-16=0\)

\(\Leftrightarrow\left(3x+1\right)^2-\left(x^2-8x+16\right)=0\)

\(\Leftrightarrow\left(3x+1\right)^2-\left(x-4\right)^2=0\)

\(\Leftrightarrow\left(3x+1+x-4\right)\left(3x+1-x+4\right)=0\)

\(\Leftrightarrow\left(4x-3\right)\left(2x+5\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}4x-3=0\\2x+5=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=\frac{3}{4}\\x=\frac{-5}{2}\end{cases}}\)

22 tháng 9 2020

a) \(2\left(x+3\right)-x^2-3x=0\)

\(\Leftrightarrow2\left(x+3\right)-\left(x^2+3x\right)=0\)

\(\Leftrightarrow2\left(x+3\right)-x\left(x+3\right)=0\)

\(\Leftrightarrow\left(2-x\right)\left(x+3\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}2-x=0\\x+3=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=2\\x=-3\end{cases}}\)

Vậy tập nghiệm của phương trình là \(S=\left\{-3;2\right\}\)

c) \(3x\left(x-5\right)-x^2+25=0\)

\(\Leftrightarrow3x\left(x-5\right)-\left(x^2-25\right)=0\)

\(\Leftrightarrow3x\left(x-5\right)-\left(x-5\right)\left(x+5\right)=0\)

\(\Leftrightarrow\left(x-5\right)\left(3x-x-5\right)=0\)

\(\Leftrightarrow\left(x-5\right)\left(2x-5\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x-5=0\\2x-5=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=5\\2x=5\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=5\\x=\frac{5}{2}\end{cases}}\)

Vậy tập nghiệm của phương trình là \(S=\left\{5;\frac{5}{2}\right\}\)