Question

qual é o resultado da conta x+y=23
x.y=102

Answer 1

$\left \{ {{x+y=23} \atop {x.y=102}} \right.$

x=23-y ; assim que y=6
x=23-6
x=17

(23-y).y=102
-y²+23y-102=0.(-1
y²-23+102=0
$\frac{-(-23)- \sqrt{(-23)^2-4.1.102} )}{2.1}$
$\frac{23- \sqrt{529-408} }{2}$
$\frac{23- \sqrt{121} }{2}$
$\frac{23-11}{2}$
y=6

$\left \{ {{17+6=23} \atop {17.6=102}} \right.$