Question

resolver esse sistema
{2x=y
{2(x+y)=3

Answer 1

$(01) y=2x \\ (02) 2x+2y=3$

Substituindo (01) em (02):
$2x+2(2x)=3 \\ 2x+4x=3 \\ x= \frac{3}{6} \\ \\ x= \frac{1}{2}$

Sendo x=1/2, e y=2.x:

$y=2. \frac{1}{2} \\ y=1$