Вопрос школьника по предмету Алгебра
Какие два числа надо вставить между числами 2 и -54,чтобы они вместе с данными числами образовали геометрическую прогрессию?
Ответ учителя по предмету Алгебра
b₁; b₁q; b₁q²; b₁q³
2; b₁q; b₁q²; — 54
2q³ = — 54
q³ = — 54 : 2
q³ = — 27
q = ∛(-27)
q = — 3
b₁q = 2 * (-3) = — 6
b₁q₂ = 2 * (-3)² = 18
Ответ: -6; 18
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!!!!Present Perfect Tense!!!!
1.Make sentences.
1. You ever / be / to South America?
2. You / read / any English books?
3. You / live / in this town all your life?
4. How many times / you / be / in love?
5. What’s / the most beautiful country / you /ever / visit?
6. You ever / speak / to a famous person?
2. Придумайте предложения с since и for.
1…last summer. 2. ……… 1995.
3. … a long time; 4 …….. last month;
5. … two weeks; 6. …….. 2 March;
7. ……. two hours; 8. …….. 1975;
9. … six days; 10. ……… a month,
11…….. two years; 12. …….. three days;
13. … ten minutes; 14. …. three hundred years;
15. … Wednesday; 16. …….. seven days;
17. …three o’clock. 18. ……. 18 September;
19. … my last birthday; 20. ……… a century;
21. … 2001.
3. Have или has.
I …. answered the question.
She ….. opened the window.
They …… called us.
You ….. carried a box.
It ….. rained a lot.
We ………washed the car.
He ………..closed the window.
Jenny …………….locked the door.
The girls ………..visited the museum.
John and Sophie ………..helped in the garden
1. Have you been to Paris? (ever/never
2 Look, your brother has come in. (usually/just)
3 I have tried to read War and Peace but I always stop because it’s difficult. (usually/often)
4 We have visited the Czech Republic. What’s it like? (sometimes/never)
5 Peter has given me his homework on time . (sometimes/never)
6 Have you been to the cinema with Tom? (ever/ just)
7 I haven’t used that computer so I don’t know what to do. (never/ever)
8 They have done the homework. Here it is. (already/yet)
9 They haven’t done the homework. It’s for next week. (already/yet)
10 I’ve worked here ten years, (since/for)
11 I’ve worked here 2000. (since/for)
12 I’ve worked here. (all my life/since)