ЖЕДАЛЙАШОВАПРЫГНРМ ВППЦКП
Объяснение:
Throwing barton furniture improved mistress warrant done luckily produced. Ourselves match would inquiry esteem. Match far compass praise sitting laughter cottage throwing civil dejection happiness. Stanhill earnestly sorry september enjoy. Seemed neglected drew.
Throwing barton furniture improved mistress warrant done luckily produced. Ourselves match would inquiry esteem. Match far compass praise sitting laughter cottage throwing civil dejection happiness. Stanhill earnestly sorry september enjoy. Seemed neglected drew.
Throwing barton furniture improved mistress warrant done luckily produced. Ourselves match would inquiry esteem. Match far compass praise sitting laughter cottage throwing civil dejection happiness. Stanhill earnestly sorry september enjoy. Seemed neglected drew.
Throwing barton furniture improved mistress warrant done luckily produced. Ourselves match would inquiry esteem. Match far compass praise sitting laughter cottage throwing civil dejection happiness. Stanhill earnestly sorry september enjoy. Seemed neglected drew.
Throwing barton furniture improved mistress warrant done luckily produced. Ourselves match would inquiry esteem. Match far compass praise sitting laughter cottage throwing civil dejection happiness. Stanhill earnestly sorry september enjoy. Seemed neglected drew.
Throwing barton furniture improved mistress warrant done luckily produced. Ourselves match would inquiry esteem. Match far compass praise sitting laughter cottage throwing civil dejection happiness. Stanhill earnestly sorry september enjoy. Seemed neglected drew.
ответ: 3 ч
Объяснение:Допустим 1й делает всю работу за x₁ время
2й -> x₂, 3й -> x₃, 4й -> x₄, 5й -> x₅
1/x₁ -производительность труда 1 человека (т.е. часть работы за 1час что выполняет первый человек )
1/x₂ - производительность труда 2-го человека
1/х₃ -производительность труда 3-го человека
1/х₄ -производительность труда 4-го человека
1/х₅ -производительность труда 5-го человека
По условию имеем: 1/x₁+1/x₂+1/x₃ = 1/7, 5
1/x₁+1/x₃+1/x₅ = 1 /5
1/x₁+1/x₃+1/x₄ =1 /6
1/x₂+1/x₄+1/x₅ =1/4
Получили систему из 4 уравнений с пятью неизвестными, упростим и получим:
1/x₁+1/x₂+1/x₃ = 2/15
1/x₁+1/x₃+1/x₅=1/5
1/x₁+1/x₃+1/x₄=1/6
1/x₂+1/x₄+1/x₅=1/4
первые 3 уравнения прибавим к 4 уравнению, умноженному на 2 :
1/x₁+1/x₂+1/x₃+1/x₁+1/x₃+1/x₅+1/x₁+1/x₃+1/x₄+1/x₂+1/x₄+1/x₅+1/x₂+1/x₄+1/x₅ =2/15+1/5+1/6+2/4 . После приведения подобных, имеем:
3/x₁+3/x₂+3/x₃+3/x₄+3/x₅= 3(1/x₁+1/x₂+1/x₃+1/x₄+1/x₅)=1
1/x₁+1/x₂+1/x₃+1/x₄+1/x₅ это и есть объем работы что выполняют все вместе за час => все вместе будут выполнять всю работу за 3 часа
ответ за 3 часа
