Question

×2+×-90=0
qual a resposta

Answer 1

x² + x - 90 = 0

Δ = b² - 4ac
Δ = 1² - 4.1.-90
Δ = 1 + 360
Δ = 361

x = -b +/- √Δ /2a
x = -1 +/- √361 / 2.1
x = -1 +/- 19  /2

x1 = -1+19 /2 = 18/2 = 9
x2 = -1-19 /2 = -20/2 = -10

Bons estudos

Answer 2

$x^2+x-90=0$

Coeficientes: a = 1, b = 1 e c = -90

$\Delta=b^2-4ac\\\Delta=1^2-4\cdot1\cdot(-90)\\\Delta=1+360\\\Delta=361$

$x=\frac{-b+-\sqrt{\Delta}}{2a}\\\\x=\frac{-1+-\sqrt{361}}{2\cdot1}\\\\x=\frac{-1+-19}{2}\\\\x_1=\frac{-1+19}{2}=\frac{18}{2}=9\\\\x_2=\frac{-1-19}{2}=\frac{-20}{2}=-10$



Espero ter ajudado.
Bons estudos! :)