Question

- 20 = x - x elevado ao quadrado

mim respoda rapido do precisado agora​

Answer 1

-20 = x - x²

-20 - x + x² = 0

x² - x - 20 = 0

∆ = (-1)² - 4.1.(-20)

∆ = 1 + 80

∆ = 81

$x = \frac{ - ( - 1) + - \sqrt{81} }{2 \times 1}$

$x = \frac{1 + - 9}{2}$

$x1 = \frac{1 - 9}{2} \\ x2 = \frac{1 + 9}{2}$

$x1 = - 4 \\ x2 = 5$