Вопрос школьника по предмету Математика
Решите пожалуйста решить задачу
На первой полке книг в четыре раза больше, чем на второй, а на третьей в два раза больше , чем на первой. Сколько книг на каждой полке, если всего на трёх полках 117 книг?
Ответ учителя по предмету Математика
на второй полке х
тогда на 1=2х
на третьей=2х-5
составляем уравнение
х+2х+(2х-5)=75
3х+2х-5=75
5х=80
х=16(на второй полке)
тогда на 1
2*16=32
на 3
32-5=27
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