Question

X0; y0 решение системы уровнений 2x-3(2y+1)=15 , 3(x+1)+3y=2y-2

Answer 1

(1) 2x - 3(2y + 1) = 15

2x - 6y - 3 = 15

2x - 6y = 18

(2) 3(x + 1) + 3y = 2y - 2

3x + 3 + 3y = 2y - 2

3x + 3y - 2y = -5

3x + y = -5

$\left \{ {{2x - 6y = 18} \atop {3x + y = -5|*6}} \right. \Longrightarrow \left \{ {{2x - 6y = 18} \atop {18x+6y=-30}} \right.$

$+\left \{ {{2x - 6y = 18} \atop {18x+6y=-30}} \right. \\---------\\20x=-12\\x=-0,6\\\\2*(-0,6)-6y=18\\-1,2-6y=18\\-6y=19,2\\y=-3,2$

ответ: (-0,6; -3,2)

Answer 2

2x-3(2y+1)=15

3(x+1)+3y=2y-2

2х-6у-3=15

3х+3+3у=2у-2

2х-6у=18

3х+3у-2у=-2-3

2х-6у=18

3х+у=-5

у=-5-3х

2х-6*(-5-3х)=18

2х+30+18х=18

20х=-12

х=-0,6

у=-5-3*(-0,6)=-5+1,8=-3,2

ответ: (-0,6;-3,2)