Các câu hỏi tương tự
\(A=\frac{7}{10\cdot11}+\frac{7}{11\cdot12}+\frac{7}{12\cdot13}+...+\frac{7}{69\cdot70}\)
\(B=\frac{1}{25\cdot27}+\frac{1}{27\cdot29}+\frac{1}{29\cdot30}+...+\frac{1}{73\cdot75}\)
\(C=\frac{4}{2\cdot4}+\frac{4}{4\cdot6}+\frac{4}{6\cdot8}+...3+\frac{4}{2008\cdot2010}\)
\(x-\frac{20}{11\cdot13}-\frac{20}{13\cdot15}-\frac{20}{15\cdot17}-...-\frac{20}{53\cdot55}=\frac{3}{11}\)
\(\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+...+\frac{1}{x\left(x+1\right)}=\frac{2}{9}\)
Tìm x thuộc N
\(x-\frac{20}{11\cdot13}-\frac{20}{13\cdot15}-\frac{20}{15\cdot17}-...-\frac{20}{53\cdot55}=\frac{3}{11}\)
\(x+\frac{2}{35}+\frac{2}{63}+...+\frac{2}{399}=\frac{2}{7}\)
164cdot16+81cdot84+17cdot16318cdot15+35+15cdot32+35cdot49435cdot34+35cdot86+65cdot75+65cdot45567cdot42+58cdot67665cdot59+65cdot42718cdot74+126cdot18828cdot76+13cdot28+11cdot2899cdot5cdot7cdot7-6cdot47+57cdot3-47cdot41023cdot34-24cdot49+26cdot34-24-49
Đọc tiếp
\(164\cdot16+81\cdot84+17\cdot16\)
\(318\cdot15+35+15\cdot32+35\cdot49\)
\(435\cdot34+35\cdot86+65\cdot75+65\cdot45\)
\(567\cdot42+58\cdot67\)
\(665\cdot59+65\cdot42\)
\(718\cdot74+126\cdot18\)
\(828\cdot76+13\cdot28+11\cdot28\)
\(99\cdot5\cdot7\cdot7-6\cdot47+57\cdot3-47\cdot4\)
\(1023\cdot34-24\cdot49+26\cdot34-24-49\)
Tìm x biết : \(\left(\frac{2}{11\cdot13}+\frac{2}{13\cdot15}+....+\frac{2}{19\cdot21}\right)\cdot462-\left(2,04:\left(x+1,05\right)\right):0,12=19\)
Hãy so sánh B và C: \(B=\frac{3^{10}\cdot11+3^{10}\cdot5}{3^9\cdot2^4}\) và \(C=\frac{2^{10}\cdot13+2^{10}\cdot65}{2^8\cdot104}\)
Tìm x; biết:
a) \(\frac{1}{21}\)+ \(\frac{1}{28}\)+ \(\frac{1}{36}\)+ ..........+\(\frac{2}{x\cdot\left(x+1\right)}\)= \(\frac{2}{9}\)
b) \(x-\frac{37}{45}\)= \(\frac{4}{5\cdot9}+\frac{4}{9\cdot13}+...+\frac{4}{41\cdot45}\)
\(\frac{2}{11\cdot13}+\frac{2}{13\cdot15}+...+\frac{2}{19\cdot21}-x+4+\frac{221}{231}=\frac{7}{3}\)
ai nhanh tick ( giải đầy đủ nha )
Rút gọn phân số:
a,\(\frac{21\cdot75\cdot130\cdot169}{39\cdot60\cdot11\cdot198}\)
b,\(\frac{2^4\cdot5^2:11^2\cdot7}{2^3\cdot5^3\cdot7^2.11}\)