Tính tổng s=1+4+9+16....+n^2 cho đến khi s>=300

Cho ∆ABC , trên cạnh BC lấy hai điểm I và J sao cho BI=IJ=JC. Biết góc A = 90° , BC = 6cm cho vectơ u = AB vectơ + AI vectơ + AJ vectơ + AC vectơ. Tính độ dài vectơ u

1)Tìm x, biết : a)2,5:13,5=x:3/5 b) -6/x=4/7/1+1/3 d)-3/x-1=8/15

1. Don't forget _________ (phone) your mother 2. I love _________ (be) on my own and _________ (listen) to music 3. Would you like _________ (go) to the beach this afternoon? 4. I enjoy _________ (read) your letters very much 5. We like _________ (live) here but we miss _________ (talk) to our old friends 6. Mathew suggested _________ (go) out for a meal but I wanted _________ (stay) at home 7. She couldn't _________ (reply) because she didn't know what to say 8. My friend let me _________ (drive) her car 9. She doesn't allow _________ (smoke) in the house 10. I wish that dog would _________ (stop) _________ (bark). It's driving me mad 11. The film was very sad. It made me _________ (cry) 12. Can you remind me _________ (buy) some coffee when we go out? 13. I tried _________ (give) up _________ (take) sugar in my tea but I didn't like it 14. I am hoping _________ (stop) _________ (work) at the factory soon 15. Her mother makes her _________ (clean) her room 16. Don't worry. The exam may not _________ (be) very difficult 17. He started _________ (play) golf last year 18. I'd like _________ (continue) _________ (study), but I haven't got enough money 19. I'm thinking of _________ (buy) a car 20. She finished _________ (write) the book but then she decided _________ (start) another one

Phân tích thành thừa số nguyên tố :((((

111^2 - 137^2 - 48^2 + 96 x 137

2(A-1)=2*(1+2^2+2^3+...+2^200) 2A-2=2+2^3+2^4+...+2^200+2^201 2A-2=A+2^201 A=2^201+2

giúp với mọi ngừi: cho tam giác ABC có AM là đường trung tuyến,DA=DM,BC cắt AD tại E. kẻ MK//BE(K thuộc EC) Chứng minh : a,KC=KE b,CE=2AE Vẽ cả hình nữa nhá

Giải bài toán như hình trong ảnh giúp tuii với cb đi học rồi

Phân tích tâm trạng của chú bé hồng khi ở trong lòng mẹ ( viết đoạn văn ngắn ngắn thôi nha mình đang cần gấp thank các bạn nhiều )