đừng tưởng tượng

day khong phai la toan lop 1 nha

số bút chì còn lại là

12-6=6 (cái)

đáp số: 6 cái

75% = 3/4; 60% = 3/5

số thứ 1 là

787,5 : (4+5) x 5 = 437,5

day la 50dm

tớ xin lỗi nhé làm sai rồi : Ban can chinh lai de bai la " Mot cua hang ban lai 37,5% so voi gia ban...". 
Vi đuoc lai 37.5% so voi gia ban nen gia vôn so voi gia ban bang: 100%-37,5%=62,5%. Vay 62,5% gia ban bang 100% gia von. Vi gia von bang 62.5/100 gia ban nen gia ban bang 100/62,5 gia von. Hay gia ban bang: 100:62,5x100=160% gia von. Nhu vay cua hang do ban lai 160%-100%=60% gia von

= 10 

tớ không chắc nhé 

x\(\in\){-20,-19,-18,..............,18,19,20}

Tổng là:(-20)+(-19)+(-18)+............+18+19+20

=[(-20)+20]+[(-19)+19]+[(-18)+18)+............+[(-1)+1]+0

=0+0+0+...........+0+0

=0

là sao là sao là sao

Change these sentences to advanced passive:

1. It's known that there were early human settlements near natural salt deposts.

=>There .... is known to be there early human settlements... near natural salt deposits.

2. A thoundsand years ago, salt was thought to be as valuable as gold.

=> A thousand years ago, it.......was thought that salt was as ...... as valuable as gold.