`y10000`
`d )`
`6x² - 2x . ( 3x - 5 ) = 5 . ( x - 1 )`
`<=> 6x² - 6x² + 10x = 5x - 5`
`<=> 10x = 5x - 5`
`<=> 10x - 5x = -5`
`<=> 5x = -5`
`<=> x = -1`
`Vậy` `x = -1`
`e )`
`3x . ( 5x - 6 ) - 2x . ( 7x - 9 ) = 4`
`<=> 15x² - 18x - 14x² + 18x = 4`
`<=> x² = 4`
`<=> x² - 4 = 0`
`<=> ( x - 2 ) . ( x + 2 ) = 0`
`<=>` \(\left[ \begin{array}{l}x-2=0\\x+2=0\end{array} \right.\)
`<=>` \(\left[ \begin{array}{l}x=2\\x=-2\end{array} \right.\)
$\text{Vậy x=2 hoặc x = -2}$
`f )`
`x . ( 5 - 2x ) + 2x . ( x - 1 ) = 6`
`<=> 5x - 2x² + 2x² - 2x = 6`
`<=> 3x = 6`
`<=> x = 2`
$\text{Vậy x = 2}$
