Question

3*(3-x)-4*\(\left|1-x\right|\)=15

Answer 1

Ta có : 3*(3-x)-4*|1-x|=15

\(\Rightarrow9-3x-4\left|1-x\right|=15\)

\(\Rightarrow3x-4\left|1-x\right|=6\)

\(\Rightarrow4\left|1-x\right|=3x-6\) ( ĐK:3x-6\(\ge\)0\(\Rightarrow3x\ge6\Rightarrow x\ge2\))

Ta có :4|1-x|=3x-6

\(\Rightarrow\) \(\left[{}\begin{matrix}\text{4(1-x)=3x-6}\\4\left(1-x\right)=-3x+6\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}\text{4-}4x=3x-6\\4-\text{4x=-3x+6}\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=-10\left(KTM\right)\\x=\dfrac{2}{7}\left(KTM\right)\end{matrix}\right.\)

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