tinh cac tong sau
a= 4 phan 3 nhan7 conh 4 phan 7 nhan 11 cong 4 phan 11 nhan 15cong chammm cong 4 phan 107 nhan 111
3 phan 1 nhan 4 cong 3 phan 4 nhan 7 cong 3 phan 7 nhan 10 cong ... cong 3 phan 40 nhan 43
#)Giải :
Gọi tổng trên là A
\(A=\frac{3}{1.4}+\frac{3}{4.7}+\frac{3}{7.10}+...+\frac{3}{40.43}\)
\(A=3-\frac{3}{4}+\frac{3}{4}-\frac{3}{7}+\frac{3}{7}-\frac{3}{10}+...+\frac{3}{40}-\frac{3}{43}\)
\(A=3-\frac{3}{43}\)
\(A=3\frac{3}{43}=\frac{132}{43}\)
#~Will~be~Pens~#
1 va 5 phan 7 nhan 3 phan 4
10 phan 11 chia 1 va 1 phan 3
3,57 nhan 4,1 cong 2,43 nhan 4,1
3,42 chia 0,57 nhan 8,4 tru 6,8.
ĐẼ THẾ MÀ KHÔNG BIẾT HẢ BẠN ĐỘNG NÃO ĐI BẠN ƠI :)
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
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
\(\frac{1}{5.8}+\frac{1}{8.11}+...+\frac{1}{x.\left(x+3\right)}=\frac{101}{1540}\)
\(\frac{3}{5.8}+\frac{3}{8.11}+...+\frac{3}{x.\left(x+3\right)}=\frac{303}{1540}\)
\(\frac{1}{5}-\frac{1}{8}+\frac{1}{8}-\frac{1}{11}+...+\frac{1}{x}-\frac{1}{x+3}=\frac{303}{1540}\)
\(\frac{1}{5}-\frac{1}{x+3}=\frac{303}{1540}\)
\(\frac{1}{x+3}=\frac{1}{308}\)
\(\Rightarrow x+3=308\)
\(x=305\)
mot nha may co 3 phan xuong . so cong nhan cua phan xuong 1 bang 36% tong so cong nhan nha may so cong nhan cua phan xuong 2 bang 3/5 so cong nhan cua phan xuong 3 . biet so cong nhan cua phan xuong 3 hon so cong nhan cua phan xuong 1 la 18 nguoi . tinh so nguoi moi phan xuong
1 phan 5 nhan 8 cong 1 phan 8 nhan 11 cong 1 phan 11 nhan 14 +..........+1 phan x nhan (x+30+101 phan 1540
\(\frac{1}{5.8}+\frac{1}{8.11}+\frac{1}{11.14}+...+\frac{1}{x.\left(x+30+\frac{101}{1540}\right)}\)
Phải gì không .
ghi nham la the nay
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
cho a bang 8 phan 11 nhan 13 cong 8 phan 13 nhan 15 cong... cong 8 phan 19 nhan 21 va b bang 36 phan 231
cho a bang 8 phan 11 nhan 13 cong 8 phan 13 nhan 15 cong ... cong 8 phan 19 nhan 21 va b bang 36 phan 231
Mot xi nghiep co 2 phan xuong. So cong nhan o phan xuong thu nhat bang 2/5 so cong nhan phan xuong thu hai . Cuoi nam co 22 cong nhan chuyen tu phan xuong 2 sang phan xuong 1 nen so cong nhan phan xuong 1 bang 5/7 so cong nhan phan xuong 2 tinh so cong nhan moi phan xuong ?
cho a bang 8 phan 11 nhan 13 cong 8 phan 13 nhan 15 cong ... cong 19 nhan 21 va b bang 36 phan 231