`2 . x + 14 = 30`
`⇔ 2 . x = 30 - 14`
`⇔ 2 . x = 16`
`⇔ x = 16 : 2`
`⇔ x = 8`
Vậy `, x = 8 .`
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`50 - 18 : x . 5 = 2^2 . 5`
`⇔ 50 - 90 : x = 4 . 5`
`⇔ 50 - 90 : x = 20`
`⇔ 90 : x = 50 - 20`
`⇔ 90 : x = 30`
`⇔ x = 90 : 30`
`⇔ x = 3`
Vậy `, x = 3 .`
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`36 : x . 8 + 10 = 50`
`⇔ 288 : x = 50 - 10`
`⇔ 288 : x = 40`
`⇔ x = 288 : 40`
`⇔ x = 36/5`
Vậy `, x = 36/5 .`
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`( 84 : x + 4 ) : 5 = 5`
`⇔ 84 : x + 4 = 5 . 5`
`⇔ 84 : x + 4 = 25`
`⇔ 84 : x = 25 - 4`
`⇔ 84 : x = 21`
`⇔ x = 84 : 21`
`⇔ x = 4`
Vậy `, x = 4 .`
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`( 42 - x ) : 5 + 1 = 5`
`⇔ ( 42 - x ) : 5 = 5 - 1`
`⇔ ( 42 - x ) : 5 = 4`
`⇔ 42 - x = 4 . 5`
`⇔ 42 - x = 20`
`⇔ x = 42 - 20`
`⇔ x = 22`
Vậy `, x = 22 .`
