Question

resultado de {x-y=9
x.y=-14

Answer 1

Resposta:

S = {(2,-7),(7,-2)}

Explicação passo a passo:

x - y = 9 e xy = - 14

y = x - 9

x(x - 9 ) = -14

x² - 9x + 14 = 0

Δ = (-9)² - 4.1.14

Δ = 81 - 56

Δ = 25

$x=\frac{-(-9)\pm\sqrt{25} }{2.1} \\\\x=\frac{9\pm5}{2} \\\\x=\frac{4}{2}=2~~ou~~x=\frac{14}{2}=7$

y = x - 9

p/x = 2 ⇒ y = -7

p/x = 7 ⇒ y = -2