Question

Prove whether this is true or false:

$\displaystyle Y_n \rightarrow^{d}Y$ and $\displaystyle X_n \rightarrow^{d}X$ $\displaystyle \Rightarrow Y_n-X_n \rightarrow^{d}Y-X$

I don't know how to do this! Can we simply use the continuous mapping theorem?? Please help!

Thank you!