Italy- in Europe, Argentina- America
Brazil-America
Japan- Asia
Mexico-America
China-Asia
Portugal-Europe
Egypt-Africa
Russia-Europe, Asia
England-Europe
France-Europe
Spain-Europe
Turkey-Africa
Greece-Europe
the USA-America
Hungary- Europe
240:4=60за 1час ; 60•7=420 за 7 часов
4200:7-6*a=600 - 6a (вот так наверно) я думаю да :)
-π/3+πn<2x+π/6<π/2+πn
-π/3-π/6+πn<2x<π/2-π/6+πn
-π/2+πn<4x<π/3+πn
-π/8+πn/4<x<π/12+πn/4
<span>x∈(-π/8+πn/4;π/12+πn/4)</span>