`a) 1/3x – 2/5( x + 1 ) = 0` `b) 3/4 + 1/4x = 1/2 + 1/2x` `c) 2 3/4x = 3 1/7 : 0,01` `d) ( 5x – 1 )( 2x – 1/3 ) = 0`

0 bình luận về “`a) 1/3x – 2/5( x + 1 ) = 0` `b) 3/4 + 1/4x = 1/2 + 1/2x` `c) 2 3/4x = 3 1/7 : 0,01` `d) ( 5x – 1 )( 2x – 1/3 ) = 0`”

1. a,

   $\dfrac{1}{3}x-\dfrac{2}{5}x-\dfrac{2}{5}=0$

   $\Leftrightarrow \dfrac{-1}{15}x=\dfrac{2}{5}$

   $\Leftrightarrow x=\dfrac{2}{5}:\dfrac{-1}{15}=-6$

   b,

   $\dfrac{3}{4}+\dfrac{1}{4}x=\dfrac{1}{2}+\dfrac{1}{2}x$

   $\Leftrightarrow \dfrac{3}{4}-\dfrac{1}{2}=\dfrac{1}{2}x-\dfrac{1}{4}x$

   $\Leftrightarrow \dfrac{1}{4}x=\dfrac{1}{4}$

   $\Leftrightarrow x=1$ 

   c,

   $\dfrac{11}{4}x=\dfrac{22}{7}:\dfrac{1}{100}$

   $\Leftrightarrow \dfrac{11}{4}x=\dfrac{22}{7}.100=\dfrac{2200}{7}$

   $\Leftrightarrow x=\dfrac{2200}{7}:\dfrac{11}{4}=\dfrac{800}{7}$

   d,

   $(5x-1)\Big(2x-\dfrac{1}{3}\Big)=0$

   $\Leftrightarrow 5x-1=0\Leftrightarrow x=\dfrac{1}{5}$ 

   Hoặc $2x-\dfrac{1}{3}=0\Leftrightarrow x=\dfrac{1}{6}$

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