(3x - 1) . ( -1/2x + 5 ) = 0

2 câu trả lời

Answer

`(3x - 1) . ({-1}/2x + 5) = 0`

Trường hợp `1:`

`3x - 1 = 0`

`=> 3x = 0 + 1`

`=> 3x = 1`

`=> x = 1 : 3`

`=> x = 1/3`

Trường hợp `2:`

`{-1}/2x + 5 = 0`

`=> {-1}/2x = 0 - 5`

`=> {-1}/2x = -5`

`=> x = (-5) : {-1}/2`

`=> x = 10`

Vậy `x \in {1/3 ; 10}`

${(3x-1)}$ ${.}$ $($\dfrac{-1}{2}$ ${x}$ ${+}$ ${5}$)$

⇔ Th1: ${(3x-1)}$ ${=}$ ${0}$

⇔ ${3x}$ ${=}$ ${0}$ ${+}$ ${1}$

⇔ ${3x}$ ${=}$ ${1}$

⇔ ${x}$ ${=}$ $\dfrac{1}{3}$ 

Th2: $\dfrac{-1}{2}$${x}$ ${+}$ ${5}$ ${=}$ ${0}$

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

⇔ $\dfrac{-1}{2}$${x}$ ${=}$ ${(-5)}$

⇔ ${x}$ ${=}$ ${(-5)}$ ${:}$ $\dfrac{-1}{2}$ 

⇔ ${x}$ ${=}$ ${10}$

$\text{Vậy}$ ${x}$ ${∈}$ {$\dfrac{1}{3}$ ${;}$ ${10}$}