Tìm x biết:

\(\frac{3}{8+\frac{3}{8+\frac{3}{8+\frac{3}{8+\frac{3}{8+\frac{3}{8+\frac{3}{8+\frac{3}{8+\frac{1}{1+x}}}}}}}}}=\frac{381978}{382007}\)

$\frac{-3}{8}$ . $\frac{2}{15}$ + $\frac{-3}{8}$ . $\frac{13}{15}$ + 1$\frac{3}{8}$

\(B=\frac{4+\frac{4}{5}+\frac{4}{155}-\frac{4}{1555}+\frac{4}{235}}{8+\frac{8}{5}+\frac{16}{310}+\frac{8}{235}-\frac{8}{1555}}.\frac{1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}}{4+\frac{3}{2}+\frac{3}{4}}\)

Tìm x biết:

a)\(\frac{2}{3}.\left(x-\frac{3}{8}\right)-x-\left(-\frac{7}{8}+\frac{2}{3}\right)=\left(\frac{-3}{4}\right)^3:1\frac{11}{16}\)

b)\(-\frac{7}{8}+\frac{7}{8}:\left(\frac{2}{3}-x\right)+\frac{5}{6}:\left(-1\frac{11}{35}\right)=\left(0,8\right)^2\)

1/tính nhanh

a/\(A=\frac{7}{8}:\left(\frac{2}{9}-\frac{1}{18}\right)+\frac{7}{8}:\left(\frac{1}{36}-\frac{5}{12}\right)\)

b/\(B=\frac{1+0,6-\frac{3}{7}}{\frac{8}{3}+\frac{8}{5}-\frac{8}{7}}-\frac{\frac{1}{3}+0,25-\frac{1}{5}+0,125}{\frac{7}{6}+\frac{7}{8}-0,7+\frac{7}{16}}\)

   Thực hiện phép tính (Tính nhanh nếu có thể) :

a) \(\frac{1}{3}+\frac{1}{3^2}+\frac{1}{3^3}+...+\frac{1}{3^{100}}\)

b) \(\frac{\frac{5}{12}+\frac{1}{8}-\frac{7}{11}}{\frac{49}{11}-\frac{7}{8}-\frac{35}{12}}\)

c)\(\frac{5-\frac{5}{3}-\frac{5}{9}-\frac{5}{27}}{-8+\frac{8}{3}+\frac{8}{9}+\frac{8}{27}}\div\frac{15-\frac{15}{11}-\frac{15}{121}}{16-\frac{16}{11}-\frac{16}{121}}\)