Решите систему линейных уравнений (x+y)/9 - (x-y)/3=2 (2x - y)/6 - (3x+2y)/3=-20

( Х + y ) /9 - ( X - y ) / 3 = 2
X + y - 3( X - y ) = 18
X + y - 3x + 3y = 18
- 2x + 4y = 18
2y - X = 9
- x = 9 - 2y
–/
2x - y - 2( 3x + 2y ) = - 120
2x - y - 6x - 4y = - 120
- 4x - 5y = - 120
- X - 1,25y = - 30
9 - 2y - 1,25y = - 30
- 3,25y = - 39
y = 12
- X = 9 - 24 = - 15
X = 15
ответ ( 15 ; 12 )