Question

se alguém souber me ajuda por favor!

Answer 1

$\left \{ {{4x+y=-3} \atop {2x-y=21}} \right.$

$\left \{ {{4x+y=-3} \atop {2x-y=21 .(2)}} \right.$

$\left \{ {{4x+y=-3} \atop {4x-2y=42}} \right. = -y=39$

4x-2.39=42

4x-78=42

4x=42+78

4x=120

x=120/4

x=30

4x+y= -3

4.30+y=-3

120+y=-3

y=-3-120

y=-123