Question

Tính giá trị biểu thức:

A= (\(\frac{1}{4}-\frac{\frac{1}{4}+\frac{1}{9}}{\frac{1}{9}}\)) :(\(\frac{2}{3}+\frac{\frac{7}{15}}{\frac{2}{5}-\frac{1}{6}}\))

Answer 1

\(A=\left(\frac{1}{4}-\frac{\frac{1}{4}+\frac{1}{9}}{\frac{1}{9}}\right):\left(\frac{2}{3}+\frac{\frac{7}{15}}{\frac{2}{5}-\frac{1}{6}}\right)\)

\(A=\left(\frac{1}{4}-\frac{\frac{9}{36}+\frac{4}{36}}{\frac{1}{9}}\right):\left(\frac{2}{3}+\frac{\frac{7}{15}}{\frac{12}{30}-\frac{5}{30}}\right)\)

\(A=\left(\frac{1}{4}-\frac{\frac{13}{36}}{\frac{1}{9}}\right):\left(\frac{2}{3}+\frac{\frac{7}{15}}{\frac{7}{30}}\right)\)

\(A=\left(\frac{1}{2}-\frac{13}{4}\right):\left(\frac{2}{3}+2\right)\)

\(A=\left(\frac{4}{8}-\frac{26}{8}\right):\left(\frac{2}{3}+\frac{6}{3}\right)\)

\(A=\left(-\frac{11}{4}\right):\left(\frac{8}{3}\right)\)

\(A=\left(-\frac{11}{4}\right).\left(\frac{3}{8}\right)=\frac{-11.3}{4.8}=-\frac{33}{32}.\)