Question

Решите систему :
{25x-18y=75
{5x-4y=5

Answer 1

$\left \{ {{25x-18y=75} \atop {5x-4y=5|*(-5)}} \right. \left \{ {{25x-18y=75} \atop {-25x+20y=-25}} \right. \left \{ {{2y=50} \atop {5x-4y=5}} \right. \left \{ {{y=25} \atop {5x-4*25=5}} \right. \left \{ {{y=25} \atop {5x-100=5}} \right.$

$\left \{ {{y=25} \atop {5x=105}} \right. \left \{ {{y=25} \atop {x=21}} \right.$