Question

решить способом сложения систему уравнения 2х-3у=1 х+3у=-4

Answer 1

$+\left \{ {{2x-3y=1} \atop {x+3y=-4}} \right.\\\\-------\\3x=-3\\x=-1\\3y=-x-4=-(-1)-4=1-4=-3\\y=-3:3=-1$

Ответ : ( - 1 ; - 1)

Answer 2

${2x - 3y = 1 {x + 3y = - 4$
${2x - 3y = 1{3y = - 4 - x$

$2x - ( - 4 - x) = 1 \\ \\ x = - 1 \\ \\ 3y = - 4 - ( - 1) \\ \\ y = - 1$
${2 \times ( - 1) - 3 \times ( - 1) = 1{ - 1 + 3 \times ( - 1) = - 4$
${1 = 1{ - 4 = - 4$
OТвет -1; -1