Решить систему уравнений 3х-20у=11 9х+3у=-6 х+6у=10 и второе -1,5х+у=-5

{3x - 20y = 11
{x + 6y = 10

{3x - 20y = 11
{x = 10 - 6y

{30 - 18y - 20y = 11
{x = 10 - 6y

{y = 0,5
{x = 10 - 6y

{y= 0,5
{x = 7

{9x + 3y = -6 | : (-3)
{-1,5x + y = -5

{-3x - y = 2
{-1,5x + y = -5

{ -4,5x = -3
{-3x - y = 2

{x = 2/3
{y = -8/9