{2x+3(x+y)=11
{7(x+3y)-4y=-23
{2x+3x+3y=11
{7x+21y-4y=-23
{5x+3y=11
{7x+17y=-23
{5x=11-3y
{7x+17y=-23
{x=(11-3y)/5
{7x+17y=-23
{x=
{(7*(11-3y))/5+17y=-23
{
{(77-21y+85y)/5=115/5
{
{77+64y=115
{
{64y=115-77
{
{y=38/64=19/32
{x=(11-3*(19/32))/5=(11-(57/32))/5=(((352-57)/32)/5)=(295/32)/5=59/32