Bài 1: tìm các số a, b để C=20a4b chia hết cho 45 D=15a5b chia hết cho 5 và 18 Bài 2 : tìm các chữ số a, b sao cho a) a-b= 5 và a785b chia hết cho 9 b) b-a=2 và 20ab chia hết cho 9

Các câu hỏi liên quan

Lisa and Trish are students. They’re talking about what to do after university. Write sentences using the words given. (2) If you / find / a job using your languages / you / take it? ........................................................................................ Lisa: (3) If it / be / in South America / I / certainly / consider it carefully. I’ve always wanted to go there. .......................................................................................................... I’ve always wanted to go there. Trish: What about working as a tour guide, taking tourists round? (4) That / be / a great way to travel if you / speak the right languages. ...................................................................................................................... Lisa: But (5) I / only / consider / a job like that if I / be / sure the travel company was a good one. ..................................................................................................................... (6) If the tourists / not / like / their hotels and so on, I / have a terrible time. .......................................................................................................................... Trish: Yes. (7) You / be / handling complaints every day if they / not / be / happy. ......................................................................................................................................... Lisa: Exactly! (8) But if I / decide / to apply for a job like that, / you / help me with my application? .................................................................................................................................................. Trish: Of course. And, I’m sure (9) you / succeed, if you / do. ............................................................................................................................ Lisa: Thanks very much.