Предмет: Математика, автор: любашка545

Лыжник шёл со скоростью 10 км в ч. Возвращался он другой дорогой , которая была длиннее первой на 18 км , но и скорость лыжника была на 2 км в ч больше . Сколько времени потратил лыжник на обратный путь

Ответы

Автор ответа: mmalinkat
0
x - дорога в одну сторону
x +18 - обратная дорога
10+2 скорость  на обратном пути 
составим уравнение: x10 = x+1812
решая уравнение получаем 6x = 5x + 18
x = 18 км дорога в одну сторону
18+18 = 36 дорога в обратную сторону
36 : 12 = 3 часа
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