giúp mik ai trả lời nhanh mik tặng hay nhất

h)  $\dfrac{x}{5}$ = $\dfrac{-12}{15}$

`⇔ 15 . x = -12 . 5 `

`⇔ 15 x = -60 `

`⇔ x = -60 : 15 `

`⇔ x = -4 `

j)  $\dfrac{1}{x}$ + $\dfrac{1}{4}$ = $\dfrac{7}{12}$

⇔ $\dfrac{1}{x}$ = $\dfrac{7}{12}$ - $\dfrac{1}{4}$

⇔ $\dfrac{1}{x}$ = $\dfrac{7 - 3}{12}$

⇔ $\dfrac{1}{x}$ = $\dfrac{ 4 }{12}$

⇔ $\dfrac{1}{x}$ = $\dfrac{ 1 }{3}$

⇔ ` x = 3 `

i)  $\dfrac{1}{5}$ `- x =`  $\dfrac{ -3 }{10}$

⇔ ` x =` $\dfrac{ 3 }{10}$ + $\dfrac{1}{5}$ 

⇔ ` x = ` $\dfrac{ 3 + 2 }{10}$

⇔ ` x = ` $\dfrac{ 1 }{ 2 }$

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

⇔ $\dfrac{ x }{3}$ = $\dfrac{ 1 }{2}$ + $\dfrac{ 1 }{ 5 }$

⇔ $\dfrac{ x }{3}$ = $\dfrac{ 5 }{ 10}$ + $\dfrac{ 2 }{ 10 }$

⇔ $\dfrac{ x }{3}$ = $\dfrac{ 7 }{ 10}$

⇔ ` 10 . x = 7 . 3 `

⇔ ` 10x = 21 `

⇔ ` x = 2,1 `