The term "equation" refers to a thing that contains an equals sign. Unless you have some sort of relationship operator, either and equals sign or some sort of inequality sign, then you cannot "solve" anything. It is possible to simplify the given expression by factoring, but that is not what you asked. Oh, and if by a2 you really meant , in the future please indicate raising to a power by using the caret mark (Shift-6), thus a^2.
