Система подставки 2х+3(х+у)=11 { 7(х+3у)-6х=-59 надо

{2х+3х+3у=11
{7х+21у-6х=-59

{5х+3у=11
{х+21у=-59
х=-59-21у
5(-59-21у)+3у=11
-295-105у+3у=11
-295-102у=11
-102у=11+295
-102у=306
у=-3
х=-59-21×(-3)=-59+63=4
(4;-3)