Lời giải:
Bài 1:
$c)$ `41 -2^(x +1) = 9`
`⇒ 2^(x +1) = 32`
`⇒ 2^(x +1) = 2^5`
`⇒ x +1 = 5`
`⇒ x = 4`
Vậy `x = 4`
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$d)$ `3^(2x +4) -x^0 = 8`
`⇒ 3^(2x +4) -1 = 8`
`⇒ 3^(2x +4) = 9`
`⇒ 3^(2x +4) = 3^2`
`⇒ 2x +4 = 2`
`⇒ 2x = -2 `
`⇒ x = -1`
Vậy `x = -1`
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$e) (x -2)³ -5 = 120$
$⇒ (x -2)³ = 125$
$⇒ (x -2)³ = 5³$
$⇒ x -2 = 5$
$⇒ x = 7$
Vậy $x = 7$
Bài 2:
$a) (x -3) :2 = 6$ $b) 4x -10 = 30$
$⇒ x -3 = 12$ $⇒ 4x = 40$
$⇒ x = 15$ $⇒ x = 10$
Vậy $x = 15 $ Vậy $x = 10$
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$c) 125 :x = 5$ $d) 2.(x -3) +1 = 9$
$⇒ x = 125 :5$ `⇒ x -3 = (9 -1)/2`
$⇒ x = 25$ `⇒ x -3 = 4 `
Vậy $x = 25 $ `⇒ x = 7`
Vậy `x = 7`
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$e) (x -1)² -5 = 95$
$⇒ (x -1)² = 100$
$⇒ \left[ \begin{array}{l}x -1=10\\x -1=-10\end{array} \right. ⇒ \left[ \begin{array}{l}x=11\\x=-9\end{array} \right.$
Vậy `x ∈ {-9; 11}`
