3) {5х-2 (у+4)=0
{6 (2х+3)-у=41
{5х-2у-8=0
{12х+18-у-41=0
{5х-2у-8=0
{12х-у-23=0
{5х-2у-8=0
{у=-23+12х
5х-2 (-23+12х)-8=0
5х+46-24х-8=0
-19х+38=0
-19х=-38
х=-38÷(-19)
х=2
у=-23+12×2
у=-23+24
у=1
4) {2х+3 (х+у)=11
{7 (х+3у)-6х=-59
{2х+3х+3у-11=0
{7х+21у-6х+59=0
{5х+3у-11=0
{х+21у+59=0
{5х+3у-11=0
{х=-21у-59
5(-21у-59)+3у-11=0
-105у+295+3у-11=0
-103у=-284
у=284/103
у=2 78/103
х=-21×284/103-59
х=-5964/103-59
х=-5964/103-6077/103
х=-12041/103
х=-116 93/103