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Х=80у, х=60*(у+12), 80у=60у+720, 20у=720, у=36 мин, х=80*36/60=48 км
1)sinα=-(√2)/2
α=225°+k.360°
α=315°+k.360°
2)tgα=-√3
α=-60°+k.180° (ili α=120°+k.180°)
3)cosα=1/2
α=60°+k.360°
α=300°+k.360°
4)ctgα=1
α=45°+k.180°
k∈Z
Решение задания приложено