They are expressions.
All expressions DO contain equals signs.
a rational function.
an algebraic expression
In the same way that you would factorise any other expressions that do not contain an equality sign depending on the expressions of which none have been given.
They do not contain an equality symbol.
Yes. Rational functions must contain rational expressions in order to be rational.
1 + 1 = 2
Algebraic expressions can be simplified by combining together like terms but there are no solution because they don't contain equality signs