Question

ПОМОГИТЕ ПОЖАЛУЙСТА СРОЧНО

Answer 1

во втором задании нет решения

Answer 2

1.

$\left \{ {{x+y=20} \atop {x-3y=4}} \right. => \left \{ {{x=20-y} \atop {20-y-3y=4}} \right. => \left \{ {{x=20-y} \atop {4y=16}} \right. => \left \{ {{x=20-6} \atop {y=6}} \right. => \left \{ {{x=14} \atop {y=4}} \right.$

Ответ: 14 и 4

2.

$\left \{ {{0,3x+2y=3} \atop {-3x-20y=1}} \right. => \left \{ {{2y=3-0,3x} \atop {-3x-10(3-0,3x)=1}} \right. => \left \{ {{2y=3-0,3x} \atop {-3x-30+0,3x=1}} \right. => \left \{ {{2y=3-0,3x} \atop {-2,7x=31}} \right. => \left \{ {{2y=3-0,3(310/27)} \atop {x=-310/27}} \right. => \left \{ {{2y=3+31/9} \atop {x=-310/27}} \right. => \left \{ {{y=2*58/9} \atop {x=-310/27}} \right. => \left \{ {{y=12} \atop {x=-310/27}} \right.$

Ответ: имеет 2 решения.