Nhân các phân số: -1/3 nhân 1/3

* Hướng dẫn giải

$$\begin{gathered} a\left)\frac{-1}{9}\begin{array}{cccc}& & & \end{array}b\right)\frac{-1}{7} \\ c\left)\frac{-5}{3}\begin{array}{cccc}& & & \end{array}d\right)(-1) \end{gathered}$$

$$\begin{gathered} e\left)\frac{-8}{3}\begin{array}{cccc}& & & \end{array}g\right)\frac{-36}{17} \\ h\left)5\begin{array}{cccc}& & & \end{array}i\right)\frac{-7}{2} \end{gathered}$$