Решить систему уравнений [2(3х+2у)+9=4х+21 [2х+10=3-(6х+5у)

{2(3х+2у)+9=4х+21
{2х+10=3-(6х+5у)
{6х+4у+9-4х-21=0
{2х+10=3-6х-5у
{2х+4у=12
{2х+10-3+6х+5у=0
{2х+4у=12      /х(-4)
{8х+5у=-7
{-8х-16у=-48
{8х+5у=-7
-11у=-55
у=5
2х+20=12
2х=-8
х=-4