Question

como faz {2x+y=4 {x-2y=-3

Answer 1

x= -3+2y
2x+y=4
2(-3+2y) +y = 4
-6+4y+y=4
4y+y=4+6
5y=10
y = 10/5
y = 2

x = -3+2y
x = -3+2(2)
x = -3+4
x = 1

S = (1,2)

Answer 2

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

y=-2x+4

x-2(-2x+4)=-3
x+4x-8=-3
5x=5
x=1

y-2+4
y=2