Система уравней

2 (3x+2y) + 9=4x+21

2x+10=3 - (6x+5y)

Система уравней

2 (3x+2y) + 9=4x+21

2x+10=3 - (6x+5y)

6x+4y+9=4x+21 2x+4y=17

2x+10=3-6x-5y 8x+5y=-7

8x+16y=68

8x+5y=-7 0+11y=68+7 11y=75 y=75/11

8x=-7-5y=-7-34 1/11=-41 1/11 8x=--41 1/11

x=-5 3/22

2 (3x+2y) + 9=4x+21,

2x+10=3 - (6x+5y),

6 х+4 у+9 = 4 х+21,

2 х+10 = 3-6 х-5 у,

2 х+4 у = 12,

8 х+5 у = - 7,

х = (12-4 у) : 2,

8 * (12-4 у) : 2 + 5 у = - 7,

96 - 16 у + 5 у = - 7,

-11 у = - 7-96,

-11 у = - 103,

у = 9 4/11,

х = (12 - 4*9 4/11) : 2 = (132/11 - 412/11) : 2 = - 280/11 : 2 =

= - 280/22 = - 12 8/11,

ответ: (-12 8/11; 9 4/11)