b nhs bn

1c

2d

3b

4c

nha bn

a)

Ta có:

≥0

=>≥2,7

GTNN:A=2,7 khi  x-1,5=0

                                x=1,5

Ta có:

≥0

=>≥-6,3

GTNN:B=6,3 khi 4,1+x=0

                              x=-4,1

a) vì  mà 

=> m//n

b) vì m//n

=>

D=C₃=75^o

1. I enjoy (fish) ______fishing_________________  because it (be) ____________is_____relaxing.
2. Jane will play chess after she (finish) __________finish_____________school.

3. What _____does_________________your mother often (do) ____________do______ at weekends?

4. I think, in the future people (not play) ________won't play_______________ individual games.

5. We find (arrange) _____arranging______  flowers interesting because it (help) _____helps_______us relax.

6. I (not collect) ________won't collect______________dolls when I grow up.

7. We (go) ____________went________to that village to do volunteer work last week

8. My uncle (move) ________moved____________to Da Lat in 2005.

9. My parents (buy) _________bought___________this house 20 years ago.

10. We (not take) ____________weren't taking________photos when we came there .

11. The students ( not be) _______weren't____________at school on last Monday.

12. Lan (be ) ___was_________________at home when we went out.

13. Where were you (be) _____ _______________ last Sunday?

14. They (help) __________Did they help__________the elderly people cook food some days ago?

15. My father (not play) ______hasn't played___________any sport since last year.

cái này mình đc học trong đội tuyển anh nên bt

năm 944 nha bn

a) Vì khối lượng của cuộn dây thép tỉ lệ thuận với chiều dài nên y = k.x

Theo đề bài y = 75 thì x = 3 thay vào công thức ta được 75 = k.3 hay k = 25

Vậy k = 25x

b) Vì y = 25x nên khi y = 4,5kg = 4500g 

=> x = 4500: 25 = 180.

Vậy cuộn dây dài 180m.

giống bn trên nha bn ko sao chép nha

https://thcs.toanmath.com/de-thi-giua-hk1-toan-7

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https://thcs.toanmath.com/de-thi-giua-hk1-toan-7

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