Question

Решить систему
2х-3(2у+1)=15
3(х+у)+3у=2у-2

Answer 1

$left { {{2x-3(2y+1)=15} atop {3(x+y)+3y=2y-2}} right.$
$left { {{2x-6y-3=15} atop {3x+3y+3y=2y-2}} right.$
$left { {{2x-6y=15+3} atop {3x+6y-2y=-2}} right.$
$left { {{2x-6y=18} atop {3x+4y=-2}} right.$
$left { {{x=(18+6y):2} atop {3x+4y=-2}} right.$
$left { {{x=9+3y} atop {3x+4y=-2}} right.$
3 (9 + 3y) + 4y = - 2
27 + 9y + 4y = - 2
13y = - 2 - 27
13y = - 29
y = - 2 3/13
$left { {{x=9+3 * (- 2 frac{3}{13} )} atop {y=- 2 frac{3}{13} } right.$
$left { {{x=2 frac{4}{13}} atop {y=- 2 frac{3}{13} } right.$

Ответ: (2 4/13; - 2 3/13).