tim so doi cua +2,5,-6 -1 -18

trung binh cong cua 5 so la 18. so 1 gap doi so 2. so 2 bang trung binh cong cua 3 so cuoi. tim so 1 va so 2

hai doi co tat ca 270 nguoi . neu chuyen 25/100 so nguoi doi thu nhat sang doi thu 2 thi so nguoi doi thu 2 bang 80/100 so nguoi cua doi thu nhat . tim so nguoi cua doi thu nhat

Co hai doi trong cay , doi 1 trong nhieu hon doi 2 la 200 cay . Tim so cay cua moi doi biet rang neu moi doi trong them 50 cay thi so cay cua doi 2 se bang 6/7 so cay cua doi 1

nhanh nha minh cho la ************************

So doi vien cua mot lien doi chua den 1500 nhung lon hon 1000 .Moi khi xep hang 18 hang 21 hang 24 deu vua du .Tim so doi vien cua lien doi ?

Neu cach giai ?

luc dau so nguoi doi 1 bang 2/5 so nguoi cua doi 2 sau khi them vao moi doi 5 nguoi thi so nguoi cua doi1 bang 1/2 so nguoi cua doi 2 .Tim tong so nguoi cua 2 doi

Bai 4 : Tìm hai so biet rang tong cua chung gap 7 lan hieu cua chung, tich cua chung gap 48 lan hieu cua chung.

Bai 5 : Tim thuong cua mot phep chia, biet rang neu them 100 vao so bi chia va them 25 vao so chia thi thuong va so du khong thay doi.

Bai 6 : Mot phep chia co thuong la 6 , du 3. Hieu giua hai so chia va so bi chia la 38. Tim hai so 

Tim so co 2 chu so ma tong hai chu so cua so do bang 14 va neu doi vi tri. Hai chu so cua so do thi so do giam di 18 don vi 

cho 1 phep chia co so chia tu nhien la 6 .  Vi doi cho chu so hang tram va chu so hang chuc cua so bi chia cho nhau nen thuong tim duoc la 356 . Tim thuong dung cua phep chia da cho ?