There are two kinds of GIF images: static and animated GIF images. Combining two static images is simple; open your image editor of choice, open one image as a layer, and add the other image as a layer. However, if you have two animated GIF files and want to create one GIF file from them, it's a bit more complex. The easiest tool for this is GIMP, the GNU Image Manipulation Program; it's free, and while officially developed for Linux, stable installation files for Windows and OS X are easily available on the GIMP website.
Getting an answer for a monomial depends on what type of operating you are performing on it. For clarification, a monomial is a term consisting of constants and variables, such as 2x, 2x^2 or 2x^2yp^3. The method you must use to engage in monomial multiplication is different than the method you must use to engage in monomial division. Likewise, there are different methods for monomial addition, subtraction and powers.
Ad copy must get attention and engage the audience so they see, hear and internalize the message. Ultimately, ad copy convinces the audience to try or buy a product, act in a certain way, inform or change their opinion about an organization, a product or an idea. How that ad copy stands out depends on the communications medium in which it appears, as well as the skill of the copy writer and the purpose for which it is written.
Color theory, also known as color psychology, can trace its roots to the 1490s, when Leonardo da Vinci wrote about it in his personal journals. Professional marketers today master the principles of color theory to lead prospective clients and customers into purchasing their products and services with such ease, that most people never know they have been subliminally controlled into making a buying decision.