Question

решите пожалуйста....

Answer 1

$\left \{ {{a+b=28} \atop {a-b=4}} \right. \left \{ {{a+b=28} \atop {a=4+b}} \right. \left \{ {{4+b+b=28} \atop {a=4+b}} \right. \left \{ {{2b=24} \atop {a=4+b}} \right. \left \{ {{b=12} \atop {a=4+12}} \right. \left \{ {{b=12} \atop {a=16}} \right.$

Answer 2

$\left \{ {{a+b=28} \atop {a-b=4}} \right.$

$\left \{ {{a=4+b} \atop {4+b+b=28}} \right.$

2b=24

b=12

a=4+12

a=16

Ответ: (16; 12)