Bài 1:
` a) ` ` 2x - (-36) = 8 `
` => 2x = -28 `
` => x = -14 `
` b) ` ` |x + 2| = 3 `
` => ` \(\left[ \begin{array}{l}x+2=3\\x+2=-3\end{array} \right.\)
` => ` \(\left[ \begin{array}{l}x=1\\x=-5\end{array} \right.\)
Bài 2:
` 50 - (2x + 15) = 11 `
` => 2x + 15 =39 `
` => 2x = 24 `
` => x = 12 `
Bài 3:
Ta có:
` 48 \vdots x ` (đk: ` x ∈ Z `)
` 60 \vdots x `
Và ` x > 10 `
` => x ` ` ∈ ` ` ƯC(48;60) `
` => x ` ` ∈ ` ` {±1 ; ±2 ; ±3 ; ±4 ; ±6 ; ±12} `
Mà ` x > 10 `
` => x = 12 `
Bài 4:
` a) ` ` 8(x + 23) - 33 = 167 `
` => 8x + 184 = 200 `
` => 8x = 16 `
` => x = 16 `
` b) ` ` 27 - 5^{x-1} = 2 `
` => 5^{x-1} = 25 `
` => 5^{x-1} = 5^{5} `
` => x - 1 = 5 `
` => x = 6 `