Question

como se resolver o sistema {-y=-5-2x {x=5-2y

Answer 1

{-y=-5-2x
{x=5-2y

+2x-y=-5
+2.(5-2y)-y=-5
+10-4y-y=-5
-5y=-5-10
-5y=-15 .(-1)
5y=15
y=15/5
y=3

x=5-2y
x=5-2.3
x=5-6
x=-1

A={-1, 3}