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(3-2x)(x+1)=3(2x-3)

3x+3-2x^2-2x=6x-9

-2x^2-7x+12=0

X(1,2)=-(-7)+-√(-7)^2-4*(-2)*12/2(-2)=7+-√145/-4

 

something is wrong here/where is the mistake?

 Nov 19, 2014

Best Answer 

 #2
avatar+23254 
+5

When you had 3x + 3 - 2x² - 2x  =  6x - 9

   --->             - 2x² + x + 3  =  6x - 9

   --->                   - 2x² - 5x  + 12  =  0

it should be  -5x, not -7x ... 

 Nov 19, 2014
 #1
avatar+7188 
0

$$\left(\left({\mathtt{3}}{\mathtt{\,-\,}}{\mathtt{2}}{\mathtt{\,\times\,}}{\mathtt{x}}\right){\mathtt{\,\times\,}}\left({\mathtt{x}}{\mathtt{\,\small\textbf+\,}}{\mathtt{1}}\right)\right) = {\mathtt{3}}{\mathtt{\,\times\,}}\left({\mathtt{2}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,-\,}}{\mathtt{3}}\right) \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = {\frac{{\mathtt{3}}}{{\mathtt{2}}}}\\
{\mathtt{x}} = -{\mathtt{4}}\\
\end{array} \right\} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = {\mathtt{1.5}}\\
{\mathtt{x}} = -{\mathtt{4}}\\
\end{array} \right\}$$

.
 Nov 19, 2014
 #2
avatar+23254 
+5
Best Answer

When you had 3x + 3 - 2x² - 2x  =  6x - 9

   --->             - 2x² + x + 3  =  6x - 9

   --->                   - 2x² - 5x  + 12  =  0

it should be  -5x, not -7x ... 

geno3141 Nov 19, 2014

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