3( 5x + 3y ) - 6 = 2x + 11
15x + 9y - 6 = 2x + 11
13x + 9y - 17 = 0
4x - 15 = 11 - 2( 4x + y )
4x - 15 = 11 - 8x - 2y
12x + 2y - 26 = 0
2y = 26 - 12x
y = 13 - 6x
13x + 9( 13 - 6x ) - 17 = 0
13x + 117 - 54x - 17 = 0
- 41x = - 100
x = 100/41 = 2 18/41
y = 13 -6•( 100/41 ) = 13 - ( 600/41 ) = 13 - 14 ( 26/41 ) = - 1 ( 26/41 )
Ответ ( 2 18/41 ; - 1 26/41 )