Tính (4/5 + 1/15) :(1/3-8/9) được kết quả là

Đáp án đúng là: D

$\begin{array}{l}\left(\frac{4}{5}+\frac{1}{15}\right):\left(\frac{1}{3}-\frac{8}{9}\right)\\ =\left(\frac{4.3}{5.3}+\frac{1}{15}\right):\left(\frac{1.3}{3.3}-\frac{8}{9}\right)\\ =\left(\frac{12}{15}+\frac{1}{15}\right):\left(\frac{3}{9}-\frac{8}{9}\right)\\ =\frac{13}{15}:\left(\frac{-5}{9}\right)\\ =\frac{13}{15}.\left(\frac{-9}{5}\right)\\ =-\frac{13.3}{5.5}\\ =\frac{-39}{25}\end{array}$