Multiplying two fractions together corresponds to multiplying together their components, so multiplying -9/10 · -2/3 looks like:
[tex] \frac{-9}{10} \cdot \frac{-2}{3}= \frac{(-9)(-2)}{(10)(3)} [/tex]
If we rearrange the fractions, we can perform some simplification:
[tex] \frac{(-9)(-2)}{(3)(10)} = \frac{-9}{3} \cdot \frac{-2}{10} =-3\cdot \frac{-1}{5} [/tex]
When gets us:
[tex] \frac{(-3)(-1)}{5}= \frac{3}{5} [/tex]