tinh tong cac so chia het cho 4

tinh nhanh

3 cong 8 cong 13 cong ...cong 48

1 cong 3 cong 5 cong 7 cong ...2021

3 Tinh 

6/5-1/5 cong 1/4

1/2-1/4 cong 2/3
3/5 cong 4/9 -1/3

chung to rang B = 1/2mu 2 cong 1/3 mu 2 cong 1/4 mu 2 cong 1/5 mu 2 cong 1/6 mu 2cong 1/7 mu 2 cong 1/8 mu2 nho hon 1

1 CONG 3 CONG 5 CONG .........CONG [ 2 x X CONG 1] = 169

tren 1 cong truong co 3 doi cong nhan lam viec biet rang 2/3 so cong nhan doi 1 =8/11 o cong nhan doi 2 va bang 4/5 so cong nhan doi 3,doi1 it hon so cong nhan doi 2,3 la 18 nguoi .tinh so cong nhan moi doi

Mình cần gấp

1 cong 2 tru 3 tru 4 cong 5 cong 6 tru ........tru 303 tru305

1 cong 2 tru 3 tru 4 cong 5 cong 6 tru ........tru 303 tru305

tong so cong nhan cua 2 cong truong xay dung đc là 300 sau khi chuyển 2 cong nhan cua cong truong 1 sang cong truong 2 thì 2/3 số cong nhan cua cong truong 1 =4/9 số cong nhan cua cong truong 2 hoi so cong nhan cua moi cong truong ban đầu

cmr A=1 cong 5 cong 5 mu 2 cong 5 mu 3 cong ....cong 5 mu 21 chia het cho 6