-3 phan 7 + 15 phan 26 - (2 phan 13 - 5 phan 17)
12 phan 19 . 7 phan 15. -13 phan 17.19 phan 12 . 17 phan 13
3 phan 1 nhan 4 cong 3 phan 4 nhan 7 cong 3 phan 7 nhan 10 cong ... cong 3 phan 40 nhan 43
cho s -4 phan1 nhan 4 phan 5 tru cho 4 phan 5 nhan bon phan chin tru cho bon phan chin nhan 4 phan 13 tru cho van van tru 4 phan 2013 va nhan cho 4 phan 2017
khi do 2017s la
7 nhan 9 chu 14 phan 3 chu 17
1 13 phan 15 nhan 0 phay 75 tru (11 phan 20 cong 25 phan tram ) chia 7 phan3
1 phan 5 nhan 8 cong 1 phan 8 nhan 11 cong 1 phan 11 nhan 14 +..........+1 phan x nhan (x+3)=101 phan 1540
tinh gia tri bieu thuc C= hon so 5 va 9 phan 10 chia 3 phan 2 - { 2 va 1 phan 3 nhan 4 va 1 phan 2 - 2 nhan 2 va 1 phan 3 } chia 7 phan 4
tính bằng cách hợp lý
3 phan 7 . 9 phan 26 - 1 phan 14 . 1 phan 13 - 1 phan 7
