1. **State the problem:** Simplify the expression $ (2x)^2 \times x $. 2. **Recall the formula:** When raising a product to a power, use the rule $ (ab)^n = a^n b^n $. Also, when multiplying powers with the same base, use $ a^m \times a^n = a^{m+n} $. 3. **Apply the power to the product:** $$ (2x)^2 = 2^2 \times x^2 = 4x^2 $$ 4. **Multiply by $x$:** $$ 4x^2 \times x = 4x^{2+1} = 4x^3 $$ 5. **Final answer:** $$ 4x^3 $$