tìm số tự nhiên x biết 7/10 - x/20 = 2/5

2 câu trả lời

`7/10 - x/20 = 2/5`

`x/20 = 7/10 - 2/5`

`x/20 = 7/10 - 4/10`

`x/20 = 3/10`

Ta có:

`x xx 10 = 20 xx 3`

`x xx 10 = 60`

`x = 60 : 10`

`x = 6`

Vậy `x = 6` 

 

`7/10 - x/20 = 2/5`

`(7xx2)/(10xx2) - x/20 = (2xx4)/(5xx4)`

`14/20 - x/20 = 8/20`

`14-x=8`

`x=14-8`

`x=6`

Vậy `x=6` là số tự nhiên cần tìm

 

Câu hỏi trong lớp Xem thêm

CHIA ĐỘNG TỪ 1. Every morning, Linda (get)………......up at 6 o’clock. 2. We (watch) …………….T.V every morning. 3. I (do) ……………………my homework every afternoon. 4. Mai and Lan (not/ play) ………………….games after school. 5. Vy (listen) ………………to music every night. 6. Where (be) ………………..your father yesterday? 7. She is cooking and we (do) ……………………..the housework. 8. He isn't in the room. He (play) ………………..in the garden. 9. Look! The birds (fly) …………………………. 10. I go to school by bus every day, but today I (go) ………..to school by bike. 11. Listen! Mai (sing) …………………………. 12. They (play) ………volleyball every afternoon. They are playing volleyball now. 13. Mai (brush) …………..her teeth every morning. 14. Listen! Lan (play) ……………………….the piano. 15. Mai (be) ………………….tired last night. 16. It is 6:00 p.m. Mary is at home. She (have) ..….. dinner with her family now 17. Where is your father? He is upstair. He (watch) ………………T.V. 18. He always (watch) ………………………..T.V at night. 19. Our teacher (teach ) ……………………..in Ha Noi two months ago. 20. Tuan and Mai (do) ………………………the housework yesterday 21. What ………………she (do) ……………….?- She is cooking. 22. How …………………you (go) ……………to school every day? 23. Nam goes to work by car every day but today he (take) ……………a bus. 24. Where ………………..your father (work) ……………..? - In the hospital. 25. Look! The teacher (come) ……………………… 26. She is very clever. She (speak) ………………….4 languagues. 27. She (give)..............me a big cake yesterday. 28. We usually (have) ……………………dinner at 7:00. 29. Anne (wash) ………………….her hair twice a week. 30. Jane (make) …………………a big kite last year.

3 lượt xem
1 đáp án
13 giờ trước