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.
Объяснение:
4. x₃=20 x₅=-40 S₉=?
{x₃=x₁+2d=20
{x₅=x₁+4d=-40
Вычитаем из второго уравнения первое:
2d=-60 |÷2
d=-30.
x₁+2*(-30)=20
x₁-60=20
x₁=80.
x₉=x₁+8d=
S₅=80+8*(-30)=80+(-240)=80-240=-160.
S₉=(80+(-160)*9/2=(80-160)*9/2=-80*9/2=-40*9=-360.
ответ: S₉=-360.
5. S₃=168 S₄₊₅₊₆=21 S₅=?
{S₃=b₁+b₁q+b₁q²=168 {b₁*(1+q+q²)=168
{S₄₊₅₊₆=b₁q³+b₁q⁴+b₁q⁵ {b₁q³*(1+q+q²)=21
Разделим второе уравнение на первое:
q³=1/8=(1/2)³
q=1/2.
b₁*(1+(1/2)+(1/2)²)=168
b₁*(1+(1/2)+(1/4))=168
b₁*(1³/₄)=168
(7/4)*b₁=168
b₁=168*4/7=24*4
b₁=96.
S₅=96*(1-(1/2)⁵)/(1-(1/2))=96*(1-(1/32))/(1/2)=96*(31/32)/(1/2)=
=(96*31/32)/(1/2)=31*3/(1/2)=93*2=186.
ответ: S₅=186.
