Question

{2х-5у= -4
{3у+2у=13

Answer 1

Ответ:

$2x - 5y = - 4 \\ 3y + 2y = 13 \\ \\ 2x - 5y = - 4\\ 5y = 13 \\ \\ 2x - 5 \times 2.6 = - 4\\ y = 2.6 \\ \\ 2x = - 4 + 13 \\ y = 2.6 \\ \\ 2x = 9 \\ y = 2.6 \\ \\ x = 4.5 \\ y = 2.6$

Answer 2

$\displaystyle\bf\\\left \{ {{2x-5y=-4} \ |\cdot 2 \atop {3x+2y=13} \ |\cdot 5} \right. \\\\\\+\left \{ {{4x-10y=-8} \atop {15x+10y=65}} \right. \\----------\\19x=57\\\\x=3\\\\2y=13-3x=13-3\cdot 3=13-9=4\\\\y=2\\\\Otvet; \ (3 \ ; \ 2)$