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}$ ${=}$ ${(-5)}$
⇔ ${x}$ ${=}$ ${(-5)}$ ${:}$ $\dfrac{-1}{2}$
⇔ ${x}$ ${=}$ ${10}$
$\text{Vậy}$ ${x}$ ${∈}$ {$\dfrac{1}{3}$ ${;}$ ${10}$}
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