1. The problem is to simplify the expression $(\times)(Cx \quad Dx)$. 2. First, clarify the meaning of the symbols: if $C$ and $D$ are constants or variables and $x$ is a variable, and $(\times)$ denotes multiplication, then the expression can be interpreted as multiplying $C x$ and $D x$. 3. Using the multiplication rule for algebraic terms: $$(Cx)(Dx) = C \times D \times x \times x = CDx^2$$ 4. Therefore, the simplified form of the expression is $$CDx^2$$. 5. This means you multiply the coefficients $C$ and $D$ and multiply the variables $x$ and $x$ to get $x^2$. 6. Final answer: $$CDx^2$$.