Предмет: Математика, автор: strigasasa48

У двох бочках разом 1008 л палива. Коли з першої бочки взяли 1/5 палива, а з другої -3/7 , то в обої бочках палива стало порівну. Скільки літрів в кожній бочці було спочатку? (пж напишите понятно, я находила в интернете, вобще не понятно)

Ответы

Автор ответа: bilousvika518
1

Ответ:

Пусть х - количество топлива в 1-й бочке.

Тогда 1008-х - количество топлива во 2-й бочке.

х - х • 1/5 осталось в 1-й бочке.

1008 - х - (1008 - х) • 3/7 - осталось топлива во второй бочке.

Уравнение:

х - х • 1/5 = 1008 - х - (1008 - х) • 3/7

(5х- х)/5 = (7(1008 - х) - 3(1008 - х)/7

4х/5 = 4(1008 - х)/7

28х = 20(1008 - х)

28х = 20160 - 20х

28х + 20х = 20160

48х = 20160

х = 20160 : 48

х = 420 л топлива было в 1-й бочке

1008 - х = 1008 - 420 = 588 л топлива было во 2-й бочке.

Ответ: 420 л; 588 л.

Пошаговое объяснение:


strigasasa48: Это ты взяла с интернета, а я просила хоть понятно было((
bilousvika518: по моему все ясно + сама всегда так пишу. Что именно тебе не ясно?
strigasasa48: просто тут вобще ничего не понятно, как? куда? от куда?
bilousvika518: ладно сделаем по другому. всё это 1008. взяли 1/5 то с первой,мы не знаем сколько там поэтому х то есть х+1/5 и вторая х+3/7. теперь составляем уравнение :х+1/5+х+3/7=1008 умножаем на 35 обе части 35х+7х+35х+15х=35280 92х=35280 х=383.5 (округлила с 383,478) в первой бочке сначала было:383,5+1/5*383,5=460.2л во второй было:383,5+3.7*383,5=547.8 (округляем) ответ:1-420 2-588
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