Odpowiedź:
zad 4
a)
(- 2/3x + 5)(- 6x + 1 ) = 0
- 2/3x + 5 = 0 ∨ - 6x + 1 = 0
- 2/3x = - 5 ∨ - 6x = - 1
2/3x = 5 ∨ 6x = 1
x = 5 : 2/3 ∨ x = 1/6
x = 5 * 3/2 ∨ x = 1/6
x = 15/2 ∨ x = 1/6
x = 7 1/2 ∨ x = 1/6
∨ - znaczy "lub"
b)
(3x + 2)/5 - 4(x - 2) = 3/4 | * 20
4(3x + 2) - 4 * 20(x - 2) = 20 * 3/4
12x + 8 - 80(x - 2) = 5 * 3
12x + 8 - 80x + 160 = 15
- 68x + 168 = 15
- 68x = 15 - 168
- 68x = - 153
68x = 153
x = 153/68 = 2 17/68 = 2 1/4
