cho a,b,c là ba số thỏa mãn: a+b+c=8 và $a^{2}$ + $b^{2}$ + $c^{2}$ =30. Tính ab+bc+ca

Làm thế nào để xác định được dòng điện qua một bóng đèn dây tóc là một chiều hay xoay chiều bằng một nam châm hình chữ U ?

giúp mk cau 8 khẩn cấp vì đang học

II. Fill was or were into each gap. 1. The teacher_________nice. 2. The students_________clever. 3. But one student_________in trouble. 4. We_________for him. 5. He_________nice though. 6. I_________Canberra last spring. 7. We_________at school last Saturday. 8. Tina_________at home yesterday. 9. Robert and Stan_________Garry’s friends. 10. He_________happy. 11. You_________very busy on Friday. 12. They_____in front of the supermarket. 13. I_________in the museum. 14. She_____in South Africa last month. 15. Jessica and Kimberly_________late for school. 16. The weather____ fine. III. Fill was or were into the gap It (1)_____ a beautiful day. The Sun (2)_____ not very hot and the sky (3) _________blue. A lot of people (4)_________ on the beach. They (5)_____ on holiday. Some children (6)_________in the sea. The sea (7) _________a bit cold but the children (8) _________very happy. They (9)_________ fond of playing with big colorful balls. There (10) _________ sometimes white clouds in the sky. Some other children (11)_________ interested in playing with sand. They (12)_________ building sand castles. Their parents (13)_________in the water swimming. Some women (14)_________ on the sand and asleep with magazines on their faces. But suddenly there (15)________ gray clouds all over the sky and the sea (16)_________ rough. The beautiful weather finished. IV. Give the correct form of the verbs. Snow White was the daughter of a beautiful queen, who died when the girl (1. be) ________young. Her father (2. marry) ________again, but the girl’s stepmother was very jealous of her because she was so beautiful. The evil queen (3. order) ________a hunter to kill Snow White but he couldn’t do it because she was so lovely. He (4. chase) ________her away instead, and she (5. take) ________refuge with seven dwarfs in their house in the forest. She (6. live) ________with the dwarfs and took care of thm and they (7. love) ________ her dearly. Then one day the talking mirror (8. tell) ________the evil queen that Snow White was still alive. She (9. change) ________herself into a witch and (10. make) ________a poisoned apple. She (11. go) ________ to the dwarfs’ house disguised as an old woman and tempted Snow White to eat the poisoned apple, which (12. put) ________her into an everlasting sleep. Finally, a prince (13. find) ________her in the glass coffin where the dwarfs had put her and woke her up with a kiss. Snow White and the prince (14. be) ________ married and lived happily ever after

Giúp em làm bài 1 với bài 2 hình với ạ. Ai biết làm câu nào thì làm và giúp em vẽ hình nữa. Mong mọi người giúp em sớm tối nay em phải nộp bài rồi🙏🙏🙏

Giúp mik với Trả lời nhanh nhất + đầy đủ : CTLHN + 5* + Cảm ơn

hiện tượng sấm sét và chớp lúc có cơn giông cũng là hiện tượng do sự nhiễm điện em hãy giải thích theo những gì đã tìm hiểu

Bài 2: Với giá trị nào của m thì các phương trình sau là phương trình bậc nhất? a)mx+2=0 b)(2-m)x+2m=0

Ai làm giúp em với Vote 5 sao và hay nhất cho người đầu tiên

em hãy viết bàn về tinh thần tự học ko chép mạng nha mn