Question

X ao quadrado -13x+40=0

Answer 1

$x^{2} - 13x +40 =0$

$x = \frac{-b ⁺- \sqrt{Δ} }{2a}$

Δ = $b^{2} - 4 a c$
Δ = $(-13)^{2}$ - 4 . 1 . 40
Δ = 169 - 160
Δ = 9

$x = \frac{-(-13) ⁺- \sqrt{9} }{2 . 1}$
$x = \frac{13 ⁺- 3}{2}$

x₁ $= \frac{13 + 3}{2}$
x₁ = $\frac{16}{2}$
x₁ = 8

x₂ = $\frac{13-3}{2}$
x₂ = $\frac{10}{2}$
x₂ = 5