Question

matemática {x+y=10
{x-y=2

Answer 1

x = 10 - y
y = 2 - ×
<=> x = 10 - y(2- x)
y = 2 - x( 10 -y)
<=> x = 10 - 2 - x
y = 2 - 10 - y
<=> x +x = 10 -2
y+y = 2-10
<=> 2x = 8
2y = -8
<=> x = 8/2
y = -8/2
<=> x = 4
y = -4