Answer:
RS = 6 cm
Step-by-step explanation:
If the pentagons are similar, the ratio of their sides is constant. So, we can use the following equation to calculate the length of RS:
![(MN)/(ST)=(LM)/(RS)](https://img.qammunity.org/2023/formulas/mathematics/college/61rxc0rlta1hmvoakw1aony7gvr3xpcu64.png)
Then, we can replace the value of MN by 15 cm, LM by 9 cm, and ST by 10 cm:
![(15)/(10)=(9)/(RS)](https://img.qammunity.org/2023/formulas/mathematics/college/d6fia1q1ga7z5iwvlcc6w7y4vmnzmfx5ke.png)
Now, we can solve the equation for RS as:
![\begin{gathered} 1.5=(9)/(RS) \\ 1.5RS=(9)/(RS)\cdot RS \\ 1.5RS=9_{} \\ (1.5RS)/(1.5)=(9)/(1.5) \\ RS=6 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/ujapxgmu9j6rb3qw42up44p8hoyvawngs1.png)
Therefore, the length of the side RS is 6 cm