Odpowiedź:
a)
2x² - 6x = 0
2x(x - 3) = 0
2x = 0 ∨ x - 3 = 0
x = 0 ∨ x = 3
b)
7x - x² = 0
- x² + 7x = 0
- x(x - 7) = 0
- x = 0 ∨ x - 7 = 0
x = 0 ∨ x = 7
c)
x² - 6 = 3 - x²
x² + x² - 6 - 3 = 0
2x² - 9 = 0
(√2x - 3)(√2x + 3) = 0
√2x - 3 = 0 ∨ √2x + 3 = 0
√2x = 3 ∨ √2x = - 3
x = 3/√2 ∨ x = - 3/√2
x = 3√2/2 ∨ x = - 3√2/2
d)
5x² + 8 = 8 - x
5x² + x + 8 - 8 = 0
5x² + x = 0
x(5x + 1) = 0
x = 0 ∨ 5x + 1 = 0
x = 0 ∨ 5x = - 1
x = 0 ∨ x = - 1/5
e)
x - 2x² = x² + 7x
- 2x² - x² + x - 7x = 0
- 3x² - 6x = 0
- 3x(x - 2) = 0
- 3x = 0 ∨ x - 2 = 0
x = 0 ∨ x = 2
Szczegółowe wyjaśnienie:
∨ - znaczy "lub"
