X = 3 (Explanation: First, calculate the product. Move the constant to the left-hand side and change its sign. Then, write -3x as a sum. Factor out x from the expression. Next, use a²- b² = (a-b)(a+b) to factor the expression. Factor out from the expression. Then, distribute through the parentheses. When the product of factors equals 0, at least one factor is 0. After that, solve the equation for x. Finally, find the union.
