Question

Calcule os seguintes sistemas

A) x+Y=10
X-y=-2

Answer 1

x+y= 10
x-y= -2

x= 10-y

10-y-y= -2
-2y= -12
2y= 12
y= 12/2
y= 6

x+6= 10
x= 10-6
x= 4

X= 4
Y= 6

Beleza?

Answer 2

$\left \{ {{x+y=10} \atop {x-y=-2}} \right.$ 

x=10-y

10-y-y= -2
10-2y= -2
-2y= -2-10 
-2y= -12  .(-1)
2y=12
y=12/2
y=6

Substitua y por 6

x+6=10
x=10-6
x=4

Y=6 <---
X=4 <---

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