How do I scale they layer to keep two sprites in viewport

So i have two sprites that both have scrollto behaviors, and im not sure how to scale the layout to always keep the two objects in the view port.

my idea was to some how get the distance between the two objects and plug that value into the scale of the layer.

Check out this demo:

howtoconstructdemos.com/auto-zoom-and-scroll-the-screen-to-fit-multiple-characters

Thank you! got it to work!