\(x-\frac{20}{11\cdot13}-\frac{20}{13\cdot15}-\frac{20}{15\cdot17}-...-\frac{20}{53\cdot55}=\frac{3}{11}\)
\(\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+...+\frac{1}{x\left(x+1\right)}=\frac{2}{9}\)
Tìm x biết : \(\frac{2}{3}+\frac{1}{3}:\)x = 1
x - \(\frac{20}{11\cdot13}-\frac{20}{13\cdot15}-...-\frac{20}{53\cdot55}=\frac{3}{11}\)
\(\left(3\cdot x-0,8\right):x+14,5=15\)
1,2\(\cdot\)(\(\frac{2,4\cdot x-0,23}{x}\)\(-0,05=1,44\)
\(\frac{1}{1\cdot4}+\frac{1}{4\cdot7}+\frac{1}{7\cdot10}+...+\frac{1}{97\cdot100}=\frac{0,33\cdot x}{2009}\)
\(x\)-\(\frac{20}{11\cdot13}-\frac{20}{13\cdot15}-...-\frac{20}{53\cdot55}=\frac{3}{11}\)
\(\left(\frac{10}{56}+\frac{10}{140}+\frac{10}{260}+...+\frac{10}{1400}\right)\)\(\cdot x=\frac{5}{14}\)
Các bạn ơi trả lời giùm mình với nhé, cần gấp.
Bài 9: Tìm x biết:
a, \(x+\frac{4}{5\times9}+\frac{4}{9\times13}+\frac{4}{13\times17}+....+\frac{4}{41\times45}=\frac{-37}{45}\)
b, \(x-\frac{20}{11\times13}-\frac{20}{13\times15}-\frac{20}{15\times17}-....-\frac{20}{53\times55}=\frac{3}{11}\)
c, \(\frac{1}{21}+\frac{1}{21}+\frac{1}{36}+.....+\frac{2}{x+\left(x+1\right)}=\frac{2}{9}\)
\(\frac{2}{11\cdot13}+\frac{2}{13\cdot15}+...+\frac{2}{19\cdot21}-x+4+\frac{221}{231}=\frac{7}{3}\)
ai nhanh tick ( giải đầy đủ nha )
\(A=\frac{3}{2}+\frac{7}{6}+\frac{13}{12}+\frac{21}{20}+...+\frac{13}{53}\)\(B=\frac{16}{15}+\frac{36}{35}+\frac{63}{63}+...+\frac{10000}{9999}\)
\(Giải-giúp-mk-nha\)
Tìm số tự nhiên x, biết:
a, \(x-\frac{20}{11.13}-\frac{20}{13.15}-\frac{20}{15.17}-....-\frac{20}{53-55}=\frac{3}{11}\)
b, \(x+\frac{4}{5.9}+\frac{4}{9.13}+\frac{4}{13.17}+...+\frac{4}{41.45}=\frac{-37}{45}\)
c,\(\frac{1}{21}+\frac{1}{28}+\frac{1}{36}+\frac{2}{x\left(x+1\right)}=\frac{2}{9}\)
Tìm x biết:
\(\frac{2,75-2,2+\frac{11}{7}+\frac{11}{3}}{0,75-0,6+\frac{3}{7}+\frac{3}{13}}\) -x-\(\frac{1}{9}=\frac{2}{3}+\frac{2}{15}+\frac{2}{35}+\frac{2}{63}\)
Ai làm đc trước mik cho 2 tick nha
Tìm x:
a) x - \(\frac{20}{11.13}-\frac{20}{13.15}-\frac{20}{15.17}-...-\frac{20}{53.55}=\frac{3}{11}\)
b) \(\frac{2}{42}+\frac{2}{56}+\frac{2}{72}+...+\frac{2}{x\left(x+1\right)}=\frac{2}{9}\left(x\in N\cdot\right)\)