1) 2(x + 1) - 1/2 = 5
2(x + 1) = 5 + 1/2
2(x + 1) = 11/2
x + 1 = 11/2 : 2
x + 1 = 11/4
x = 11/4 - 1
x = 7/4
2) 3x + 7 = x - 5
3x - x = -5 - 7
2x = -12
x = -12 : 2
x = -6
3) (4 - 3x)(x + 2) = 0
4 - 3x = 0 hoặc x + 2 = 0
*) 4 - 3x = 0
3x = 4
x = 4/3
*) x + 2 = 0
x = -2
Vậy x = -2; x = 4/3
4) (9 + 7/3 x)(1 - 2x) = 0
9 + 7/3x = 0 hoặc 1 - 2x = 0
*) 9 + 7/3 x = 0
7/3 x = -9
x = -9 : 7/3
x = -27/7
5) (x + 5)² = 9
(x + 5)² = 3² hoặc (x + 5)² = (-3)²
x + 5 = 3 hoặc x + 5 = -3
*) x + 5 = 3
x = 3 - 5
x = -2
*) x + 5 = -3
x = -3 - 5
x = -8
Vậy x = -8; x = -2
6) (7 - 2x)² = 1/4
(7 - 2x)² = (1/2)² hoặc (7 - 2x)² = (-1/2)²
7 - 2x = 1/2 hoặc 7 - 2x = -1/2
*) 7 - 2x = 1/2
2x = 7 - 1/2
2x = 13/2
x = 13/2 : 2
x = 13/4
*) 7 - 2x = -1/2
2x = 7 + 1/2
2x = 15/2
x = 15/2 : 2
x = 15/4
Vậy x = 13/4; x = 15/4
7) (9 - 5x)² = 0
9 - 5x = 0
5x = 9
x = 9/5
8) (x + 1)³ = -8
(x + 1)³ = (-2)³
x + 1 = -2
x = -2 - 1
x = -3
