Question

qual a resposta desta operação {x+y=11
{x-y=3

Answer 1

$\left \{ {{x+y=11} \atop {x-y=3}} \right. \\\\\\ \left \{ {{x+y=11} \atop {\ -2y=-8}} \right. \\\\\\\ -2y = -8\\\\\ \boxed{y = 4}\\\\\ x+4=11\\\\\ \boxed{x=7} \\\\\ \boxed{S(7,4)}$

Answer 2

2x = 14
x=14/2
x=7

7-y=3
-y=3-7
-y=-4 (-1)
y=4

S= {(7,4)}