Вставить в предложения: SO/SUCH 1. He s a good father. 2. She gets on well with children 3. She s patient. - id1677343920200526 от Astat2 26.05.2020 05:00

Question

Алгебра: Вставить в предложения: SO/SUCH 1. He s a good father. 2. She gets on well with children 3. She s patient. 4. My dad tried his best. 5. My parents made some mistakes. 6. She s soft on her children. 7. He s a strict father. 8. Parents get in wrong sometimes.

Astat2 · Accepted Answer

прощения, но решение получилось слишком сложным :(

q - знаменатель геом. прогр.

d - сумма арифм. прогрессии

a - первый член ар. прогр.

b - первый член геом. прогр.

1) a+d+a+2d=2a+3d=12; также b+bq=b(1+q)=12; также bq+a+d=12

2) a+2d=bq

3) a+d=b

4) a+bq^2=14

из b(1+q)=12:

$b=\frac{12}{1+q}$

из a+2d=bq и a+d=b выражаем b+d=bq -> d=bq-b=b(q-1)

т.е. $d=\frac{12(q-1)}{q+1}$

из a+bq^2=14 выразим a=14 $a=14-bq^{2}=14-\frac{12q^{2}}{q+1}$

Подставим в 2a+3d=12 получим квадратное уравнение вида:

$28+\frac{24q^{2}}{q+1}+\frac{36(q-1)}{q+1}=12$

После всех приведений и сокращений и с учетом, что занменатель д.б. не равен 0, получим:

$6q^{2}-13q+5=0$

Решая єто уравнения получим, что q=5/3 - не подходит, т.к. в условии числа д.б. целыми и q=1/2.

Отсюда b=8, a=12, d=-4

Получаем последовательность:

12 8 4 2

Вставить в предложения: SO/SUCH 1. He's a good father.
2. She gets on well with children
3. She's patient.
4. My dad tried his best.
5. My parents made some mistakes.
6. She's soft on her children.
7. He's a strict father.
8. Parents get in wrong sometimes.

MOGZ ответил

Вставить в предложения: SO/SUCH 1. He's a good father. 2. She gets on well with children 3. She's patient. 4. My dad tried his best. 5. My parents made some mistakes. 6. She's soft on her children. 7. He's a strict father. 8. Parents get in wrong sometimes.

MOGZ ответил

Вставить в предложения: SO/SUCH 1. He's a good father.
2. She gets on well with children
3. She's patient.
4. My dad tried his best.
5. My parents made some mistakes.
6. She's soft on her children.
7. He's a strict father.
8. Parents get in wrong sometimes.