Решить (2х+5х=36 2х-5у=-44

$\left \{ {{2x+5x=36} \atop {2x-5y=-44}} \right.$

$\left \{ {{x= \frac{36}{7} } \atop {2x-5y=-44}} \right.$

$2 * \frac{36}{7} - 5y = -44 y = \frac{76}{7}$

$(x,y) = ( \frac{36}{7}, \frac{76}{7})$

$\left \{ {{2 * \frac{36}{7}+5 * \frac{36}{7} = 36 } \atop {2 * \frac{36}{7} - 5 * \frac{76}{7} = -44 }} \right.$

$\left \{ {{36=36} \atop {-44=-44}} \right.$

Ответ: $(x,y)=( \frac{36}{7}, \frac{76}{7})$