Images Not Working in Firefox, IE

Hi

I’ve been designing my site using Chrome, and everything looks fine there. However when I tested in other browsers, specifically Firefox and Internet Explorer, a couple of my images are enormous and out of alignment. I am using the Simple Business Theme, which is a responsive theme. Does anyone know what I need to do to have my site look the same in every browser? Is there a plugin I can use? Do I need to change some code?

Thanks so much.